V 




Class X^_"3J£_0 

Book 4^3- 



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COPYRIGHT DEPOSIT. 



STEEL 



ITS SELECTION, ANNEALING, 

HARDENING AND 

TEMPERING 



This Work was Formerly Known as The American 
Steel Worker? It is the Standard Work on Hardening, 
Tempering and Annealing Steel of All Kinds, Being 
Comprehensive and Giving Specific Instructions as 
well as Illustrations of the Methods of Hardening a 
Large Number of Tools. All Kinds of Annealing and 
Muffle Furnaces, Blast Ovens, Open Flames and the 
Use of the Lead and Cyanide Baths are Fully De- 
scribed. Case Hardening and Pack Hardening are 
Treated in a Comprehensive Manner. A Practical 
Book for the Machinist, Tool Maker, Blacksmith, 
Tool Hardener or Superintendent. 

By E; R. MARKHAM 




FOURTH EDITION. FULLY ILLUSTRATED. 







New York 






THE 


NORMAN 


W. HENLEY 


PUBLISHING 


CO. 




132 Nassau Street 








19 13 







^1° 






Copyright 1903 and 1906 
ByE.R. MARKHAM 

Copyright 1913 
By THE NORMAN W. HENLEY PUBLISHING CO. 



/3-5#?tK 



fay* 
CI.A332750 
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Words are not adequate to express the debt 
I owe one, who, more than all others, has been 
instrumental in instructing, advising and assisting 
me along lines that have led to whatever success 
I may have attained. 

As an humble acknowledgement of my grat- 
itude, I dedicate this work 

To My Father, 

RUSSELL MARKHAM. 



Preface to Fourth Revised Edition. 

The rapid progress made in American steel manu- 
facture and treatment with the constant improvement and 
invention of new processes and special steels has necessi- 
tated a revision of the present volume with numerous 
additions regarding the most recent methods of special- 
steel treatments. The advent of the automobile, the mod- 
ern gas engine and aeroplanes has brought about a de- 
mand for extremely tough, strong, high grade steels of 
various kinds known as Alloy Steels. The exact compo- 
sition of these new steels is held as a trade secret by the 
manufacturers and in fact it is very doubtful if the 
makers themselves know exactly what the steels contain. 
In a general way analysis will show the various propor- 
tions of the different metals and chemicals entering into 
their composition but doubtless the rare gases, metals and 
chemicals, which to great extent influence the final quality 
and grade of these alloy steels, are consumed or altered 
in the process of manufacture and do not appear in the 
ultimate product. Although known to the trade as 
"Tungsten steels : Vanadium steels, Chrome and 
Nickel steels," etc., yet nearly all are complex alloys 
and practically every manufacturer has a different method 
or process of producing them. For automobile and other 
special uses these alloy steels have proved of inestimable 
value and several manufacturers, notably the Ford Com- 
pany, have carried on expensive and exhaustive tests of 
such steels and in fact in this line of work have outdone 
the steel manufacturers themselves, as well as the U. S. 



Preface to Fourth Revised Edition. 

Government experts. Space will not permit of a full 
discussion or account of the modern alloy and high-speed 
steels or their treatment and all that can be done in a 
volume of the scope and size of the present work is to 
give a brief account of the more important points of 
annealing, hardening, tempering and case-hardening of 
modern steels with such data and specifications of their 
strengths, compositions and properties as can be ascer- 
tained. While the majority of users of modern steels 
guard their methods of treatment as carefully as do the 
steel manufacturers, yet there are notable exceptions to 
this rule and my thanks are especially due to the Bantam 
Anti-friction Company of Bantam, Conn., for informa- 
tion furnished regarding the heat and hardening treat- 
ment of their world-famous ball- and roller-bearings as 
well as to the C. S. Mersick Company, the Malleable Iron 
Fittings Company, and others for data and information 
furnished. 



?==^9 




CO 

Introduction. 

An experience which covers twenty-five years of 
actual practice, in the various branches of machine 
shop work, has taught the writer that much more 
depends on the condition of the various cutting tools 
used, than mechanics in general realize. 

The various machines used in working iron and 
steel to shape have been improved, and made heavier 
in the parts subjected to strain, in order that heavier 
cuts and faster feeds might be taken to reduce the cost 
of production. 

If a tool is doing the maximum amount of work 
possible for it to do, when it is used in a light machine, 
it would be folly to purchase a heavier, stronger ma- 
chine and use the same tool in it. But it has been 
found in many cases that cutting tools could be made 
that would take heavier cuts and faster feeds than the 
older types of machines could carry. Consequently it 
has been necessary to re-design most types of machines 
used to remove stock, in order to bring them into 
shape to be used as tools, parts of machines, and other 
apparatus. 

Competition has made it absolutely necessary that 
every possible means be taken to reduce the cost of an 



Cheapening cost of production. 

article without reducing the quality. Where possible 
the design is changed so the article may be made more 
cheaply. And as labor is, generally speaking, the princi- 
pal factor to be considered, it is necessary to reduce as 
far as possible the number of operations, or simplify 
those necessary, and so reduce the cost of the manu- 
factured article. 

If by the use of machinery especially adapted to 
the work to be done, it is possible to do in one opera- 
tion the work which formerly required four separate 
operations, then the amount paid for labor has been 
very materially reduced, without necessarily reducing 
the pay of the operator. In fact it is found possible in 
many cases to increase his compensation, and at the 
same time reduce the cost per piece of work very 
materially. 

Now, in order that improved machinery may do its 
maximum amount of work per day, it is necessary to 
have the cutting tools, fixtures, etc. , made in a manner 
that allows them to do their part of the work. If a 
milling machine were bought and set up in a shop, and 
it was found that the fixtures formerly used in holding 
the pieces of work were not strong enough to hold 
them when the new machine was taking the heaviest 
cut possible, heavier fixtures would be made at once in 
order that the investment of money made in purchas- 
ing the machine might not be considered as having 
been thrown away. Following out the same line of 
reasoning, it would be necessary to make cutting tools 
of a design that made it possible to take as heavy cuts, 
and use as coarse feeds, as the strength of the machine 
and fixtures would allow. 

While manufacturers in general recognize the im- 

3 



Waste through improper handling. 

portance of having machines especially fitted for their 
needs, many times the good work stops right at this 
point. They are not educated to a point that makes 
it possible for them to comprehend the importance of 
having the cutting tools hardened in a manner that 
insures their doing the amount of work possible. 

While it is often necessary to re-design cutting 
tools to get added strength, many times this needed 
strength may be had by proper hardening. 

A manufacturer of a high grade tool steel, in con- 
versation with the writer, said, if he could have one per 
cent, of the value of steel in this country spoiled by 
improper hardening, he would not exchange his income 
for that of the President of the United States. By the 
value of steel, he meant its value at the time the article 
was hardened. A piece of steel which cost fifty cents 
in the bar, may be worth many dollars when ready for 
hardening, and represents to the manufacturer the 
total cost of steel and labor. 

This line of reasoning might be carried a great 
deal further. If a tool which is made to do a certain 
job is ruined, the time the machine or machines stand 
idle waiting for another one to be made, many times 
represents a greater loss than the money value of the 
tool. This is especially true where the time given to 
complete the job is limited. 

If a tool is hardened in a manner that makes it 
impossible for it to do as much or as good work as it 
ought, the loss may be greater than in either of the 
cases before cited, yet this loss is seldom taken into 
consideration. 

The writer's experience has convinced him that 
few mechanics realize the vast waste of time in many 



Increase of productive efficiency. 

shops, because tools are not capable of doing the amount 
of work possible were they properly hardened. Take 
for instance a milling machine cutter which runs at a 
periphery speed of thirty-six feet per minute, milling a 
mild grade of machinery steel. It is found necessary 
to stop this machine once in twenty working hours to 
sharpen the cutter, milling in the meantime five hun- 
dred pieces. A cutter is made from the same bar, and 
hardened by a process that makes it possible to run the 
tool at a periphery speed of eighty feet per minute, and 
it is then found necessary to grind but once in two hun- 
dred hours; milling in the meantime eight thousand 
pieces. Not only is the efficiency of this machine 
increased many fold, but the expense of grinding, and 
the necessary delay incident to stopping the machine, 
changing cutters and setting up, and the cost of tools 
per piece, is reduced very appreciably. 

Does some one ask, How is this trouble to be 
remedied? The answer is, men must be educated to 
see the enormous waste going on all the time; the 
waste of steel, of time required to make the tools, of 
the time valuable equipment is laying idle, and the 
small percentage of work produced per machine, all go 
to reduce dividends, and this because so little attention 
is given a subject which should receive as much con- 
sideration as any one branch of machine shop work. 

When the trouble is apparent, then it is necessary 
to find a remedy. The physician must necessarily un- 
derstand the human body in order that he may diagnose 
diseases. If one would be a successful hardener of 
steel, he must understand the nature and peculiarities 
of steel. As a study of drugs alone would not fit one 
to practice medicine, neither will practice alone fit one 

10 



Necessity for the study of steel. 

to harden steel, especially if new problems are con- 
stantly coming up. 

At the present time when libraries are accessible 
to nearly every one, and books and mechanical journals, 
treating on steel and the proper methods of its manipu- 
lation, are within the reach of all, there is no good 
reason why ignorance of a subject so interesting, and 
at the same time of such vital importance to both 
manufacturer and mechanic, should be so general. 

A study of the nature of steel will convince one of 
the importance of extreme carefulness when heating 
either for forging, annealing or hardening. A man 
who understands the effect of heat on high carbon tool 
steel is often amazed at the careless manner which 
many old blacksmiths assume when heating a piece of 
steel. A difference of ioo to 200 degrees of heat after 
the steel is red hot, does not, according to their idea, 
injure the steel in the least, but in reality it makes a 
vast amount of difference in the strength of the piece. 

In some shops a man is called a successful hard- 
ener if he is fortunate enough to avoid cracking the 
pieces he is called upon to harden. Apparently no 
account is taken of the capability of the tool to perform 
a satisfactory amount of work. A man who devotes 
his attention to hardening steel in a manner to avoid 
cracking, regardless of the utility of the tool, is not 
worthy of the title of a successful hardener; he should 
be styled, as an eminent mechanic calls this class, 
a non-cracker. Now, it is possible to harden steel in a 
manner that does away with the liability of cracking, 
yet gives it the amount of hardness necessary, in order 
1 hat it may do the amount of work expected of it. 

A study of the effects of expansion and contraction 



Expansive properties of steel. 

of steel in the fire and baths is necessary in order to 
select the proper forms of furnaces and bath, so that 
the best results may be obtained. Suppose a micro- 
meter is left for some time in a room where the tem- 
perature is 40 degrees Fahr., a piece of work is placed 
between the contact surfaces, as shown in Fig. 1. 




Illustrating expansion of steel. 

Now grasp the micrometer by the frame at the portion 
marked t>, with a warm hand; in a few seconds the 
metal will have expanded to a degree that allows the 
work a to drop from the gauge, thus proving that but 
a very small amount of heat, is needed to expand the 
steel sufficiently so the contact points no longer touch 
the piece between them. 

Now, if a few degrees of heat will expand steel so 
it can be readily observed, it is apparent that a heat of 
900 to 1,200 degrees Fahr. must cause the process of 
expansion to be carried to a much greater extent. The 
amount of heat necessary to give steel, in order that it 
may harden when plunged in some cooling bath, varies 
with the make of steel, the percentage of carbon it con- 



Desirability of not overheating. 

tains, and also on the percentage of other hardening 
elements in the steel. Jarolinech places the critical 
temperature at 932 degrees Fahr. (500 Centigrade) as 
determined by him experimentally. The lowest heat 
at which a piece of steel will harden satisfactorily is 
termed the refining heat, because the effect of the 
operation of suddenly cooling steel heated to this tem- 
perature is to refine the grain, making it the finest pos- 
sible. 

The writer does not propose giving a scientific 
explanation of the changes which take place in a piece 
of steel when it is heated to the hardening heat, and 
quenched in the cooling bath, but the practical sides of 
the question will receive careful attention. 

Every man and boy working in a machine shop 
knows that steel heated red hot and plunged in water, 
will harden, but it is necessary to know how hot it 
must be heated in order that satisfactory results may 
follow. We should thoroughly understand the action 
of too great an amount of heat on the structure of steel, 
in order that overheating may be avoided. It is also 
necessary to have a correct understanding of the effects 
of baths of various kinds on steel, if it is dipped in 
them when red hot. 

It is 'an acknowledged fact that the lowest possible 
heat at which steel will harden, leaves it the strongest 
This is illustrated elsewhere. Knowing this, it will be 
seen that an article made of steel is very much less 
liable to crack when hardened at a low heat, than if it 
were heated to a temperature which caused it to be 
brittle. 

Commencing with cold steel, every degree of heat 
applied changes in a measure the size and structure 

J 3 



Uniform expansion in heating, 

of the piece, until a certain limit is reached. Now, if a 
change in temperature of a few degrees changes the 
size of a piece of steel, the reader is asked to imagine 
the change in size and structure which must take place 
when it is heated red hot. This means a change in 
temperature of about 1,000 degrees, and the effect of 
heat on steel is to expand it, while the opposite effect 
is accomplished when it is cooled. The more rapidly 
it is cooled the harder it will be. It is indeed wonder- 
ful that a piece of steel can undergo the changes which 
take place in its size and structure, and remain intact. 
When steel is cooled in the hardening bath, the outside 
of course chills and hardens first, while the inside is 
hot and consequently soft for some little time after- 
ward. Now, the outside, being hardened, is practically 
inflexible, while the inside continues to change in 
structure until cold. This is especially true of pieces 
having teeth or projections on their surface. 

Understanding the fact that heat causes steel to 
expand, it will readily be seen that it is absolutely 
necessary that it should expand uniformly throughout 
the piece. If the corners and edges are hotter than the 
balance of the piece, then it is unevenly expanded, and 
consequently will contract unevenly. Now, if one part 
of a piece of steel contracts more than another, or not 
uniformly with another part, it is liable to crack from 
the effects of the unequal contraction; if it is not 
cracked when taken from the hardening bath, it is liable 
to crack at some future time for no apparent reason 
This applies especially to large pieces, and steel having 
a high percentage of carbon. 



H 



The Workman. 




CO 



The writer's professional experience in the various 
methods of working steel, brings him in contact with 
men of all degrees of intelligence. Some men are 
really skillful in the particular line they are engaged 
in; that is, they are very careful when heating and 
dipping in the bath, and get excellent results. But 
they do not know the difference between a steel of ^ 
per cent, carbon and one of i^ per cent ; in fact, they 
do not know anything about percentages of carbon, 
and don't care; they say so in as many words. The 
steel they use is always the same make and temper. 
They have never used anything else. If they should 
get hold of another make, that worked differently 
from that they had always used, they would condemn 
it, saying it was no good, because it didn't act just like 
the steel they were accustomed to handling. 

Now, if anything should happen to the steel mill 
making their particular brand, they would be obliged 
to learn the art of hardening all over again, or go out 
of business. When it becomes necessary, or the con- 
cern who employs these men considers it advisable, 
to change the steel used; or if it is necessary to 
have the composition changed to get some desired re- 
sult, this poor fellow is all at sea. He doesn't know 

15 



The workman who "knows it all." 

what to do, and he doesn't want anyone to tell him 
what to do. His only cry is, " The steel isn't good for 
anything," when in reality it may be the best on the 
market. Such a man is to be pitied, but he is a very 
expensive man for those in whose employ he happens 
to be, and a very unpleasant fellow to attempt to teach 
anything. 

Another example is the man who banks on his 
twenty or fifty years' experience, and considers that 
because he has been allowed to exist for that length 
of time and occupy a position as blacksmith, or 
hardener, that he must necessarily know it all. To 
him steel is steel; he treats it all alike. If there is 
some particular steel good-natured enough to stand his 
treatment, that is the only brand on the market fit to 
use — according to his way of thinking — and he gener- 
ally has such an unpleasant and forcible personality, 
that he either has his say or goes where he can. He 
never investigates the merits of different makes of 
steel ; simply condemns every make that will not stand 
his abuse. 

If every man of the type under consideration ad- 
vocated using the same steel, there might be a plausi- 
ble excuse for looking into the merits of that particular 
brand, to the exclusion of every other, but you will 
hardly find two of them advocating the use of the same 
steel. I am happy to say this class of hardener is not 
in as great a majority as formerly; their number is 
gradually diminishing. It is impossible to teach him 
anything, because that long experience of his stands in 
the way ; it is his only stock in trade, and he presents 
it every time anything is said on the subject. 

Now, a long experience in any particular line of 

16 



The workman who doesn't care. 

work is a good thing for a man, provided it has been a 
real experience, rather than an existence, and in no line 
of business is it more valuable than in the working of 
steel, if the man has kept pace with the procession. 
If not, then he is no farther advanced than when 
he fell out of line, and as it is a law governing all our 
lives, that no man stands still, he must of necessity 
either advance or go backward. The man who has not 
kept pace with the progress of events, must necessarily 
go backwards. 

Another class we meet with is the jolly, good- 
natured fellow, who wants to please everybody, but 
does not know how, and is too lazy to find out. He had 
rather tell a story than to keep his eyes and attention 
on the piece he is heating, consequently he has all 
kinds of luck. There is no remedy known for this 
chap. He is willing to be told how to do, but is too 
lazy to assimilate and put in practice what is told him. 

A class of hardeners which are few in numbers, 
but who should get into some other business as soon 
as possible, consists of men who are practically color 
blind. They cannot distinguish between the various 
shades of red, neither can they discern the temper 
colors as closely as they should. Some of them are 
extremely intelligent, capable men, but they have 
missed their calling, and missed it most decidedly, 
because a man to be a successful blacksmith or hard- 
ener, must have good powers of distinguishing colors 
and shades. 

There are many other classes that might be con- 
sidered, but it would be a waste of time, so we will 
look in upon the successful hardener. There are vari- 
ous degrees of success, but we will consider the man 

17 



The successful steel worker. 

who is a success according to the generally accepted, 
idea. 

The successful hardener is one who finds out what 
is wanted or expected of the article he is to harden; 
whether extreme hardness, toughness or elasticity, or a 
combination of two of these qualities. He also under- 
stands the nature and pecularities of the steel he is 
using ; he considers the fire he is to use, and the bath 
in which the steel is to be quenched after it is heated. 

His spare moments are not spent hanging around 
street corners, or saloons, but in reading and studying 
such books and mechanical journals as treat on subjects 
in his line. In this way he becomes familiar with the 
nature of steel and knows what to do when certain 
conditions which are out of the ordinary arise ; he gets 
the experience of others and his knowledge makes it 
possible for him to discriminate between that which 
will be of value to him, and that which will not. 

When a piece of work is given him he studies the 
shape of the piece, the best method of heating and 
quenching, in order to get the desired results. To him 
steel is not simply steel, which must be treated just 
like every other piece of the same metal, but it is a 
valuable tool or piece of machinery which he takes 
pride in hardening in the best possible manner. If he 
hears of a brand that is giving some one trouble, he is 
anxious to get a piece of it, and experiment and find 
out why they can not get good results from it. 

If he hears of a brand that some one claims gives 
extra good results when using, he is anxious to get a 
sample and test it, and see for himself if the steel is 
all the makers claim it is. 

He is not above learning, takes advantage of every 

18 



The two kinds of steel. 

opportunity to get the ideas and experience of others, 
especially men who have had a wide experience. To 
him the articles he is called on to harden represent so 
much money entrusted to his care, and he takes every 
means possible to get it out in a satisfactory manner. 

Does some one ask, where do you meet such men? 
The writer is happy to say such men are not the ex- 
ception. To be sure they are not in the majority, but 
the number of men who are making a careful study of 
this subject is really encouraging. 



Steel. 



CO 

Although there are many makes of steel and, in 
most cases, several grades of the same make, yet to the 
average mechanic there are two kinds of steel, viz., 
machinery steel and tool steel. 

Machinery steel is used in making such parts of 
machines, apparatus or tools as do not require harden- 
ing in order to accomplish the result for which they 
are intended. Or, if they require hardening at all, it is 
simply a surface hardening, the interior of the piece 
being soft with a view to obtaining greater strength. 
This class of steel is of a lower grade than tool steel. 
It is softer, works more easily, both in the operations 
of forging and machining, and can be safely heated to 
a higher temperature without harm to the steel. It 



Tool steel — what it is ; what it's for. 

resembles more closely wrought iron and is sometimes 
scarcely to be distinguished from it. Machinery steel 
is used whenever it will answer the purpose, not only 
on account of its being more easily machined, but its 
first cost is only % to ^ that of ordinary tool steel, 
and for most purposes where it is used, it answers the 
purpose as well or better. 

Although it is considered advisable to group steel 
under two heads, as mentioned, namely, machinery 
steel and tool steel, yet on account of the different 
grades of the article under each head it will be neces- 
sary to distinguish them somewhat as they are con- 
sidered under the various processes of hardening. 

Tool steel is made with the idea in view that it is 
to be made into such tools, appliances or parts of 
machines as require hardening in order to accomplish 
the desired result. Although the term "tool steel" 
is applied to steel intended to be made into cutting 
tools, there are many makes of this article, each make 
differing in some respects from every other make. Not 
only is this so, but most makers put out tool steel of 
different tempers. Now, the word "temper," as used 
by steel makers, means the quantity or percentage of 
carbon the steel contains. It is low temper, medium, 
or high, or number or letter so and so, according 
to the understanding of the marks in each particular 
mill. The following are considered by steel makers as 
the most useful tempers of tool steel: 

Razor temper (i)4 per cent, carbon). This steel 
is so easily burnt by being overheated that it can only 
be placed in the hands of very skillful workmen. 
When properly treated it will do many times the work 
of ordinary tool steel when working hard metals, etc. 



Percentages of carbon in tool steel. 

Saw file temper (i^ per cent, carbon). This steel 
requires careful treatment, and although it will stand 
more heat than steel of i y 2 per cent, carbon, it should 
not be heated hotter than a low red. 

Tool temper (1% per cent, carbon). A very useful 
temper for turning tools, drills and planer tools in the 
hands of ordinary workmen. 

Spindle temper (i}£ per cent, carbon). A very 
useful temper for mill picks, circular cutters, very 
large turning tools, screw thread dies, etc. 

Chisel temper (i per cent, carbon). An exceed- 
ingly useful temper, combining, as it does, great 
toughness in the unhardened state, with a capacity of 
hardening at a low heat. It is well adapted for tools 
where the head or unhardened end is required to stand 
the blow of a hammer without snipping off, and where 
a hard cutting edge is required, such as cold chisels, etc. 

Set temper ("/% per cent, carbon). This temper is 
adapted for tools where the surface only is required to 
be hard, and where the capacity to withstand great 
pressure is of importance, such as stamping or pressing 
dies, etc. 

The following also gives the steel maker's mean- 
ing of the word " temper " : 

Very hard 150 carbon + 

Hard 100 — 120 carbon 

Medium 70 — 80 carbon 

In. order that the reader may understand some- 
thing of the significance of the terms used to designate 
the amount of carbon a piece of steel contains, the fol- 
lowing brief explanation is given. A point is one 
hundreth of one per cent, of any element. 100 points 
is one per cent. A 40 point carbon steel contains forty 

21 



Peculiarities of tool steel. 

one-hundreths (.40) of one per cent, of carbon. The 
same explanation applies to any element that goes into 
the composition of steel. The steel is sometimes desig- 
nated by the number of points of carbon it contains — 
as 20 carbon or 60 carbon steel. The amount of carbon 
the steel contains does not necessarily determine the 
quality of the steel, as the steel maker can give an 
ordinary low grade stock a very high percentage of 
carbon. This would harden under the ordinary condi- 
tions, but would be practically useless if made into 
cutting or similar tools. 

It becomes necessary many times to procure a low 
grade steel having as low a percentage of carbon as 
possible. Then again it is advisable, where a greater 
amount of strength is required, to give the steel a 
higher percentage of carbon. This will be briefly 
alluded to from time to time under the various topics. 

The reader will readily see from the foregoing that 
it is the presence of carbon in steel that causes it to 
harden. The amount of hardness and the degree of 
heat necessary when hardening depending on the 
quantity of carbon the steel contains. Tool steel is 
hardened by heating it red hot and plunging into some 
cooling bath. The more quickly the heat is extracted 
the harder the piece will be. 

Tool steel has certain peculiarities which must be 
understood if one would be a successful hardener. The 
outside surface of a bar of steel, as it comes from the 
steel mill or forge shop, is decarbonized to a consider- 
able depth. This is because the action of the oxygen 
in the air causes the carbon to be burned out of the 
steel at the surface during the various operations when 
the steel is red hot. In order that the decarbonized 



Decarbonized surface of steel. 

portion may not give trouble, it is necessary to cut 
away enough of the surface to remove this portion 
before hardening. If a tool which is to finish % inch 
diameter is to be made out of round steel, it is neces- 
sary to select stock at least x- 6 - inch diameter larger than 
the finished tool, or the outer surface will not harden 
sufficiently. For sizes from ^ to i inch diameter, 
select stock -^ to }i inch larger. For sizes from i to 
2 inches diameter, select stock from }i to -^ of an inch. 
For sizes above 2 inches, about % of an inch should be 
cut off. 

It is necessary when centering round steel to have 
the center hole very near the center of the stock, as 
shown in Fig. 2, in order to take off an equal quantity 





Figure 3. 
Proper and improper centering. 

of the decarbonizing surface all around. If a piece is 
centered, as shown in Fig. 3, the decarbonized surface 
will be entirely removed from one side of the piece 
and scarcely any of it taken from the opposite side ; 
consequently, the side from which it was removed 
will be hard, while the opposite side will not harden, 
or at least will not be as hard as the other side. 

23 



Extravagant economy. 

So it will be very readily seen that this simple fact, 
which is often entirely overlooked in machine shops, 
is a cause of a great amount, of trouble. 

Tool makers, as a rule, understand this fact in 
regard to steel, but some one in authority, wishing to 
save money for the manufacturing concern, gives the 
job of centering to the " tool room kid," as he is termed 
many times. He fails to instruct him in the proper 
manner, the boy does not understand the nature of 
steel, and as a consequence, it is centered, as shown in 

Fig. 3- 

Now, if the tool maker were given the job, he 
would readily see that it was centered wrong. But the 
spirit of economy still prevails, and the boy is allowed 
to rough out the piece. As a consequence, the outside 
surface is removed, and all traces of the eccentric cen- 
tering are eliminated. The piece is made into a reamer 
or some other tool, and when hardened it is soft on one 
side, the other side being hard enough. There is no 
one that can be blamed but the hardener, so he, poor 
fellow, has to "catch it." It wouldn't be human 
nature to stand by and say nothing when blamed for 
something one didn't understand, so he, in turn, says 
the steel is no good. 

As a consequence, the make of steel is often 
changed and another kind is procured, and as it is 
desirable to test the steel before making any quantity of 
it into costly tools, the tool maker is told to cut off a 
piece of the stock and make a reamer just like the 
one that wouldn't harden properly. He centers the 
piece, as shown in Fig. 2, turns it to size, cuts the teeth 
and gets it ready for hardening. It comes out all 
right. The steel is pronounced O. K. and a supply is 



No mysteries in steel handling. 

ordered. A large batch of reamers is made up and the 
same boy is given the job of centering and "roughing " 
them, and the results are the same or worse than when 
the former lot was hardened. Now, it is evident to 
every one that the hardener must be to blame. He 
hardened one reamer from this same steel and it was 
satisfactory. Well, the only conclusion is that he made 
a mistake when he did that one, and isn't on to his busi- 
ness, so he is nagged and found fault with until he can 
stand it no longer and gets out. The next man has 
the same results, and those in charge say, "You can't 
get a decent hardener now-a-days." All this trouble 
and expense because some one wanted the reputation 
of being a good manager. 

Now, a boy ca?i center and rough out stock and do 
it all right, but he must be told how and he must be 
watched. If a make of steel that gives satisfaction 
suddenly shows freaks, do not at first condemn the 
steel, but look for the cause. Many people have the 
idea that there are unaccountable mysteries connected 
with tool steel, and that hardening is a thing which 
must be attended with luck, or bad results follow. 
Now, as a matter of fact, if a good steel is used, the 
cause may be found for all troubles which occur when 
it is hardened, and many times they will be found to 
result from some penny wise and pound foolish notion. 

Another peculiarity of steel is that if the position 
of any of its molecules is disturbed when the steel is 
cold, there is apt to be trouble when the piece is 
hardened. For instance, if a piece of steel that is to 
be hardened for any given purpose is cut from a bar 
of tool steel and it is found to be so bent that it would 
be impossible to turn and make straight and remove 

*5 



Steel of different makes vary. 

all the decarbonized surface, the piece should be heated 
red hot and straightened. If it were straightened cold, 
then finished to size and hardened, it would be almost 
sure to spring. The writer has seen men at work 
making blanking dies for punching press work who, 
when they made the openings too large at any point, 
would take a hammer and pene the stock into the 
opening without heating the die. They would plane 
the top of the die for shear and then finish it and swear 
about the hardener when the piece cracked in harden- 
ing directly under where they pened. Possibly, it 
would not show any bad results at that time, but 
when the die was used, the portion referred to would 
crack off. Or if the punch were a tight fit, it would 
lift a piece of steel from the face of the die the shape 
of the hammer pene or of the set used. 

Steels of different makes vary in their composition. 
A successful hardener will experiment with a new steel 
and find out just what he can do with it. One make of 
steel will harden at an extremely low heat ; another make 
will not harden in a satisfactory manner at that heat. 
It requires a higher heat in order to harden it. Now, 
if we were to heat the first steel as hot as we were 
obliged to heat the other, w^e should ruin it, or at least 
harm it. For this reason it is not advisable, generally 
speaking, to have a half a dozen different kinds or 
makes of steel around a shop, unless someone knowing 
the nature and peculiarities of each is to do the harden- 
ing. And even then trouble will follow unless a ticket 
accompanies each tool stating the kind of steel, and 
this in the ordinary machine shop would lead to end- 
less confusion. 

A steel which gives satisfactory results should be 

26 



Steel is usually all right. 

selected and then used until convinced that some- 
thing better is to be had. The judgment of an ex- 
perienced hardener is not always to be relied upon as 
to the best brand of steel for a particular purpose. It 
may be that he has had excellent results with a certain 
brand because he has methods of hardening particularly 
fitted to that brand of steel; but it may be true that 
were he to change his methods to adapt them to 
another steel, much better results would follow. 

The writer was at one time brought in contact 
with a hardener whose complaints in regard to the 
steel furnished had caused the superintendent of the 
shop to change the make of steel several times. Each 
time a new steel came into the shop the result was the 
same, until finally by the advice of one of the steel manu- 
facturers several tools similar to those previously hard- 
ened with unsatisfactory results were made from each 
of the condemned steels and given to a man who was 
considered an expert hardener. When they were hard- 
ened and returned they were all found to be in a satis- 
factory condition, not a crack visible in any of them. 
They all gave good satisfaction, proving that the 
man rather than the steel was at fault. 

Almost any of the leading makes of steel in the 
market will give good results if treated properly, but 
the same treatment will not answer for all makes. 
Some makes are more satisfactory than others for 
certain purposes, but better results may be obtained 
from most of them than is often the case. 

Steel may be purchased in bars of various shapes. 
The more common shapes are round, square, flat and 
octagon. If steel is to be cut from the bar and ma- 
chined to shape, it is advisable to purchase bars which 

^7 



The choice of proper steel. 

allow of machining- to the desired shape, at the least 
expense and with as little waste of material as possible. 
Always remember that it is necessary to remove the 
decarbonized portions previously mentioned. 

If a tool which is to be cylindrical in shape is to be 
made, use a piece of round steel. If an article which 
is to be finished square, use a piece of square steel, etc. 

Steel of the same quality and temper is furnished 
in all the common shapes on the market. It was for- 
merly considered necessary, if best results were de- 
sired, to use octagon steel when making- cylindrical 
pieces of work, but now all steel makers claim to 
make round steel of exactly the same quality as the 
corresponding sizes of octagonal shape, and the exper- 
ience of every mechanic who has tested the two under 
similar circumstances substantiates the claim. 

The steel maker puts on the market steel of dif- 
ferent tempers, but he advocates the use of the par- 
ticular temper which he considers best adapted to the 
work in the individual shop. As a rule he does not 
make any mention of any other temper, because he 
knows that if steel of several different tempers are kept 
in stock, that in all probability the labels will be 
removed in a short time and any distinguishing marks 
be thrown away. Then no one in the shop will know 
one temper from another, and when a piece of ^ per 
cent, carbon steel is made into a shank mill or similar 
tool, and a piece of i^ per cent carbon steel is made 
into some tool that must resist the action of heavy 
blows, trouble will follow and the steel be condemned. 
For this reason it is considered advisable to advocate 
the use of a temper that will give satisfactory results 
when put to most uses. But the fact remains that 

*8 



Carbon necessary to proper results. 

steel, in order to give best results, should contain the 
proper percentage of carbon for use on the particular job. 
In shops where detail is followed very closely, the 
steel is kept in a stock-room, each different temper by 
itself, and so marked that there is no danger of it get- 
ting mixed. Much better results are then obtained, 
provided a competent man does the hardening, than if 
one temper was used for everything. But in a shop 
where there is only one rack, and sometimes no rack, 
the stock, machinery steel, tool steel, and everything 
else is kept on this one rack, or in a pile on the floor, it 
is not advisable to have steel of different tempers 
lying around, or results anything but satisfactory are 
sure to follow. 



Percentage of Carbon Necessary to Produce 
Desired Results. 

In the first part of this section is given a table of 
percentages of carbon present in steel for various pur- 
poses. This table is generally accepted as a guide to 
those desiring steel for any given purpose, and, gen- 
erally speaking, it is safe to use stock of the tempers 
given, but modern competition has made it necessary 
to harden steel harder and yet have it able to stand 
more than was formerly the case. When these condi- 
tions prevail, it is necessary many times, especially in 
the case of cutting tools, to use steel having a higher 
percentage of carbon than is given in the table. 

When steel containing a higher percentage of car- 
bon is used, then extra care must be observed when 
heating. For the operations of forging, annealing, or 

29 



No one steel best for all purposes. 

hardening high carbon steels should not under any cir- 
cumstances be given to a careless workman, or to one 
not thoroughly familiar with the effects of heat on 
steel of this character. 

When high carbon steels are used and treated 
properly, they will do more work than steels contain- 
ing a lower percentage, but unless they are to be 
handled by a competent man, they generally prove to 
be a very unsatisfactory investment. 

When long articles which are to be hardened are 
made of tool steel, the writer has had excellent results 
by taking the steel as it came from the bar, or after it 
was roughed out for annealing, or even after it was 
forged in the smith's shop, by heating it to a forging 
heat. Then, standing it on end on the anvil, or on a 
block of iron on the floor — if it were long — and giving 
it one or more blows on the end with a hand hammer or 
sledge; the weight of the hammer depending on the 
size of the piece. This operation is sneered at by many 
expert steel workers, but the writer's experience con- 
vinces him that better results will follow when the 
piece is hardened, if this precaution is taken, the ten- 
dency to spring is apparently greatly reduced. Should 
the piece be bent by the operation, it should be straight- 
ened while red hot, because if straightened cold, it most 
surely will spring when hardened. 

The writer has no intention of advertising any 
make of steel, as he does not believe any one make is 
best for all purposes, but experience has convinced him 
that some makes of steel give better results for certain 
purposes than others, also that some makes are better 
adapted for "all around " use than others. 

If a party is using a steel with unsatisfactory 
30 



Cheap steel not necessarily cheap. 

results, it is advisable to take measures to ascertain 
whether the trouble is in the steel, or in the method of 
working it. The writer has seen one of the best steels 
on the market condemned and its use discontinued, 
because the workman who did the hardening had been 
accustomed to a steel containing a lower percentage of 
carbon. The steel he recommended was adopted, the 
results so far as hardening were concerned were satis- 
factory, but the tools did not produce nearly the 
amount of work they should. 

After a time, the services of an expert were sought. 
He advocated the use of the very steel they had dis- 
carded. A tool was made from it, the expert harden- 
ing the tool. When put to actual use, it proved itself 
capable of doing many times the amount of work 
between grindings that could be obtained from low 
carbon steel. 

The hardener, like a sensible man, allowed the 
expert to instruct him in the proper methods to pursue, 
with the result that he became one of the best hardeners 
the writer has ever had the pleasure of meeting. 

A steel should never be selected because it is cheap, 
because it often happens that the steels which sell for the 
least money are the dearest in the end. It is possible 
to put $100.00 worth of work on a piece of steel costing 
25 cents. Now, if the tool was found useless when 
hardened, then $100.25 nas been expended in vain. 
On the other hand, if steel adapted to the purpose had 
been used, and it had cost 50 cents, there would have 
been a clear saving in money of nearly $100.00. This 
is not an exaggerated comparison, as such cases are 
frequently met with by the writer. 

On the other hand, it is folly to pay 75 cents a 

3* 



"Pipes" in steel bars. 

pound for steel, when 16 cents will buy one exactly 
suited to the job. Good steel is cheaper at any price 
it would be apt to bring in the open market, than steel 
not adapted for the purpose would be if it were a gift. 
A steel not adapted to the purpose is dear at a?vy price. 

The writer has had charge of tool rooms employ- 
ing large numbers of tool makers, and experience has 
convinced him that it is a saving of money in every 
case to test every bar of tool steel received into the 
shop that is to be made into tools. 

If the steel is kept in the stock-room, the stock 
keeper can — when the hack saw, or cutting off machine 
is not in use— cut a piece from the end of each bar, 
stamping the piece cut off and the bar alike. These 
pieces can be given to an experienced hardener, to 
heat them to the proper hardening heat, and quench 
them in a bath of water or brine. After they are 
thoroughly dry, break as near across the center as pos- 
sible, examining the center of fracture for pipes. A 
pipe is a cavity which of course makes the bar un- 
sound. It may run the entire length of the bar. If a 
bar having a pipe is discovered, the steel maker will 
gladly replace it with a sound bar. Any make of steel 
is liable to have cavities of this kind, although the 
inspector at the mill generally discovers it in the ingot, 
thus preventing it being made into bars ; but it some- 
times escapes even the most careful inspection. 

If a tool costing $50.00 were made from a bar that 
was piped, it would in all probability go all to pieces in 
the bath when hardened, unless the tool were of a 
character that allowed the piped portion to be re- 
moved. It is safer, however, to inspect the bar before 
any costly tools are made from it. If the bar proves 

3* 



Inspection an economy. 

sound, the grain should he examined; if this is fine, 
and of the proper appearance, it may be tested for 
hardness with a file. 

If the piece proves to be all right, the oar may be 
stamped. O. K. or given some distinguishing mark; 
should it prove otherwise, the manufacturer should be 
notified and the steel returned to the mill. 

This system of inspection may seem like a need- 
less waste of money, but the cost of one tool which is 
of no use when finished, would pay the necessary 
expense of testing all the steel used in a machine shop 
of the ordinary size in five years. 

When a tool is required to do extra hard work, that 
is, cut hard stock, or run at a higher speed than is 
ordinarily employed in the shop, it is advisable to get 
a steel having a greater percentage of carbon than the 
steel used for tools for ordinary work. When high 
carbon steels are bought, they should be distinctly 
labeled or stamped, and kept by themselves away from 
the rest of the steel, because if the identity of the 
piece is lost, it is liable to be made into tools and hard- 
ened without the hardener knowing that it differs in 
composition from the steel ordinarily used. As a con- 
sequence he would heat it to the same temperature he 
was accustomed to give the steel regularly used, and it 
would in all probability be cracked from the heat which 
was higher than was necessary. 



31 



Methods of Heating. 



^=^9 




The method employed when heating steel for any- 
particular purpose depends on the facilities furnished 
by the individual shop. As it is not, generally speak- 
ing, the office of the hardener to purchase the equip- 
ment of the shop ; but to use such equipment as may 
be furnished him, it is necessary that he adapt himself 
to circumstances as he finds them. The successful 
man is one who makes the best use possible of the 
equipment furnished him. 

If there are but a few tools to harden, and they are 
of a character that could be treated in a satisfactory 
manner in an ordinary blacksmith's forge, it would not 
be considered advisable to purchase a costly furnace, 
even though it were known that the work could be done 
more cheaply per piece, because the limited number. of 
pieces would not warrant the extra outlay of money for 
equipment. 

On the other hand, if work was to be done in large 
quantities, it would be wise to procure the necessary 
equipment to do the work in a satisfactory manner at 
the least cost possible. If the total amount of harden- 
ing done in a shop in any one year was 6 or 7 diamond 
point turning tools and 2 or 3 side tools, it would be 
folly to invest several hundred dollars in a muffle fur- 
nace and an elaborate system of baths. But if the pro- 
duct of the shop was several hundred taps, reamers or 

34 



Hardener should do his best. 

similar tools per day, it would not be considered good 
business policy to heat them for hardening in an ordin- 
ary blacksmith's forge. It would not be possible to 
do the work as cheaply, neither would it be done in as 
satisfactory a manner as though apparatus especially 
adapted to this class of work were used. 

But, as previously stated, the hardener should make 
the best possible use of apparatus furnished him. If 
obliged to use a blacksmith's forge for heating steel 
either for forging or hardening, he should see that his 
fire is clean and that it is high enough above the blast 
inlet so no jet of air can strike the heated steel. 

It is possible to heat comparatively small articles 
in a satisfactory manner in an ordinary forge by using 
care in regard to the size and condition of the fire and 
the location of the piece of work in relation to the 
blast inlet. 

It is always advisable to build a fire large and high 
enough so that the portion of the piece being heated 
will be covered to a considerable depth by the coals. 
Otherwise the action of the oxygen in the air would 
cause the carbon to be burned out of the surface of the 
steel, leaving it decarbonized ; in this condition it can- 
not harden. 

If the cold air from the blast strikes heated steel, 
it causes it to crack, particularly if there are teeth or 
projections, as these are more susceptible to the action 
of heat and cold than the heavier portions. The steel 
would expand from the action of the heat, the air 
striking the projections would cause contraction, and 
the repeated expansion and contraction would cause 
the steel to crack. 

If large pieces are to be hardened, a large high 

35 



Action of charcoal on steel. 

fire should be built, as a low fire in a forge having a 
tuyere — blast inlet — of the ordinary .size would not be 
sufficiently large to heat the piece uniformly. It is 
always advisable when heating large pieces to use a 
fire of new coals if charcoal is used as fuel, as coals 
which have been used for some time are burned to the 
extent that the fire is dead unless considerable blast is 
used, in which case the result would be a lot of cracked 
work. 

Charcoal is generally considered the ideal fuel to 
use when heating tool steel. As it is a form of carbon, 
it is generally given credit for imparting carbon to the 
steel heated in it. Now, this is the case, if low carbon 
steels are packed in a tube or box with a good quality 
of charcoal, away from the action of the fire and air, 
and run for a considerable length of time. Carbon will 
then be absorbed by the steel. Before the process of 
making crucible steel was discovered, iron bars or rods 
were packed in tubes with charcoal and run for a suffi- 
cient length of time to charge the iron with carbon, 
thus making a union of iron and carbon, or steel, as 
it is familiarly known. This process is known as 
"cementation." 

It does not seem probable that a piece of tool steel, 
high in carbon would absorb any extra carbon in the 
brief time it was exposed to the action of fire, in heat- 
ing for hardening. On the contrary, if a piece of high 
carbon steel is heated in this manner, it is apt to lose 
some of the carbon at the surface. For this reason, a 
piece of high carbon steel is not so liable to have sur- 
face cracks if heated for hardening in a charcoal fire. 
But from experiments, it can, I think, be truthfully 
claimed that a piece of 1.5 per cent, carbon steel will 

36 



The use of muffle furnaces. 

not be as hard on the surface if heated in a charcoal 
fire, as if heated in a fire burning coke. 

But if steel must be heated in a fire, exposed to 
the action of the burning fuel, it is advisable in most 
cases to use charcoal, because it does not contain im- 
purities injurious to the steel. 

On the other hand, high carbon steel will not be as 
hard on the surface if heated in a charcoal fire, as if 
heated in some form of furnace where the article is not 
exposed to the action of the burning fuel, and as most 
of the other fuels contain impurities injurious to the 
steel, it is best to heat in a manner that removes it 
from the action, not only of the burning fuel, but also 
from the action of the air. In order to accomplish the 
desired result, the article may be placed in a tube or 
iron box, or a muffle furnace may be used. 

If many pieces are to be hardened, it is advisable 
to procure a furnace especially adapted to the class of 
work. The neatest, most easily managed furnace, and 
the one which gives as good satisfaction as any, is a 
form made to burn illuminating gas as fuel. These 
can be procured of almost any size. A very satisfac- 
tory style of this type is known as a muffle furnace, 
from the fact that the piece of steel to be heated is placed 
in an oven or muffle. The flame circulating around 
the muffle heats it to any required degree of heat. 
The steel is heated by radiation, consequently it is not 
subjected to the injurious effects of the products of 
combustion; and as the door may be closed, there is 
little danger of oxidation of the heated surface. If the 
furnace is not provided with some means whereby the 
work being heated may be readily observed without 
removing the door, it is advisable to drill one or two 

r 



Types of muffle furnaces. 



one-inch holes in the door, covering them with mica. 
These furnaces are by far the most satisfactory for 
general use of any form the writer has used. Figs. 4 

and 5 represent 
two styles of 
these furnaces. 
If it is not con- 
sidered advis- 
able to purchase 
a furnace of this 
description and 
one is to be 
made on the 
premises, it is 
possible to make 
a very satisfac- 
tory furnace 
quite cheaply. 
If large or long 
pieces are to be 
heated and a 
furnace is to be 
made of a type 
where the steel 
is placed in con- 
t a c t with the 
fuel, it is advis- 
able to use char- 
coal, as either 
coke or coal do 
not f u r n i s h a 
the circumstances 
The grate should be, made the size of the 

38 




-/"The Deiry ColUrd Co, 

Figure 4. Muffle furnace for hardening. 

satisfactory means of heating under 
mentioned. 



Types of muffle furnaces. 



inside of the furnace, as in this way a uniform heat 
may be maintained in all parts of the furnace, and it 
will not be necessary to use a blast. A natural draft 
will be found sufficient. 

Fig. 6 shows a furnace of the type mentioned, the 
dimensions depending- on the size and character of the 
work to be heated. 
A damper should be 
placed in the smoke 
pipe in order to check 
the fire if there is 
danger of its becoming 
too hot. This damper 
should not be of the 
type usually put in the 
pipe of a coal stove, as 
these dampers are made 
with a hole to allow for 
the escape of gas. It is 
not desirable to have 
this hole in the damper, 
as it is impossible to 
check the fire on a 
windy day. The lower 
door must also be fur- 
nished with a damper, 

, , - . , Figure 5. 

m order to furnish 

draft when desired. It is possible with this furnace 

to do very excellent work. 

If it is desirable to build a muffle furnace, one 
may be made to use either charcoal, coke, or hard coal 
as fuel by taking the one represented in Fig. 7 as a 
model, and changing the design to meet the require- 

39 




Muffle furnace for hardening. 



"Home-made" muffle furnaces. 

ments. The interior of the muffle is represented by A, 
B is the fire box, C the ash pan. The heat and smoke 
passing up from the fire box follow the direction of the 
arrow passing under the muffle and out of the smoke 
pipe at D. A damper should be placed in the smoke 



/-\ 




J;tr u Co. 
Figure 6. A "home-made" furnace. 

pipe and one in the ash chamber door. By means of 
these dampers the draft can be regulated very nicely. 
This form of furnace works very nicely in heating 
dies and similar work. 

When small articles are hardened in large quan- 
tities a furnace may be made of the design shown in 

40 



Home-made" muffle furnaces. 



Fig. 8, where a represents the fire box which burns 
hard coal, charcoal or coke; b the ash box; and c the 
chamber for heating the work. The front plate has a 
number of holes corresponding to the number of tubes 
it is considered advisable to heat at a time. The tubes 
are made by taking a gas pipe, plugging one end as 





The Derry Collard Cu. 

Figure 7. A "home-made" furnace for burning 
charcoal, coke or hard coal. 

shown as Fig. 9, the other end being left open. A 
number of pieces of work may be placed in each tube 
and the tubes placed in the openings. The tubes at 
the bottom will heat more quickly than those at the 
top, so it is advisable when a tube in the bottom row 
is taken from the furnace to fill its place with one from 
one of the top rows. The tubes as they are filled may 
be placed in the top rows and allowed to heat gradually 

41 



"Home-made" muffle furnaces. 

and later removed and placed in the lower row. By 
following this plan it is possible to heat the work 



o o o o 

o o o 
o o o o 




The Derry Collard Co. 



Figure S. A "home-made" furnace for 
heating small pieces. 

gradually and yet harden a large amount of work in a 

given time. The tubes should be turned occasionally 

in order to insure even heating and satisfactory results. 

When but a few small pieces are to be hardened 



. ., . 


.. .,,,. 




','■'/'// ' '■■:'.'/ 




W//////J 


, ; - , 




. . ,..-... ; ; 



The Deny Collard Co. 

Figure 9. Construction of tubes in 
"home-made" furnace. 



a gas blast of the form shown in Fig. 10 answers very 
nicely. If the pieces are of a size that guarantee their 



4* 



Apparatus for heating small number of pieces. 

heating quickly it is safe to hold them in the flame, 
having a piece of fire brick to reflect the heat. By 
this means the heat is utilized to much better advan- 
tage than if nothing were placed back of the work. It 



O^ 




The Deny Collard Co. 
Figure 10. Gas blast for heating a few pieces. 

is possible by forming a cavity in the brick or making 
a small oven as shown in Fig. 1 1 to heat a much larger 
piece of work in an ordinary blow pipe than would 
otherwise be the case. 




Figure 1 1 . Another form of gas blast for heating 



A crude but satisfactory method of economically 
heating small pieces is furnished by the idea presented 
in Fig. 12, in which case a small oven is built of fire 
brick, or a casting of the desired shape may be 

43 



Gas blasts for heating a few pieces. 

obtained. In either case a flame from gas blast should 
enter at one or both sides through holes provided. 

Small articles may be heated by using a Bunsen 




Figure 12. Small "home-made" gas blast oven. 



burner, as shown in Fig. 13, which can be applied to a 
gas pipe in place of the ordinary burner, or may be 
connected by means of a piece of rubber tube. When 
using a burner of this description the work can be 
heated more readily if a piece of sheet iron is placed 
over the burner at the proper height, the article to be 
heated being placed beneath this, the sheet metal 
reflecting the heat and thus increasing its utility. 

It is also possible by means of a blow pipe to heat 
very small articles sufficiently for hardening by means 
of an ordinary gas jet or the flame of a spirit lamp, as 
shown in Fig. 14. This is an expensive method when 
work is heated in quantities, but answers very nicely 
for one or two pieces. 

When heating for forging or any work where the 
outside of the steel is afterwards to be removed it is 

44 



Heating small articles. 



advisable to use a form of furnace where the direct 
heat of the fire comes in contact with the steel, as it is 
much more economical and is, generally 
speaking, a quicker method than heating 
in a muffle furnace. It is advisable many 
times when heating large pieces of steel 
for hardening, to use a furnace, as de- 
scribed, on account of economy. In case 




Tbe Derry Collurd Co. 

Figure 14. The blow pipe 
way of heating. 

the outer decarbonized surface is to be 
ground away, the results will be satisfactory ; 
but if the outer surface must be hard, then 
it is necessary to protect the 
surface from the action of 
the products of combustion. 
This may be accomplished 
by several different methods. 



The Derry Collard Co 

Figure 13. Bunsen burner, for 
heating small articles. 



45 



Covering paste, and how to make it. 

One method is to place the portion of the piece, which 
must not be decarbonized, in a box with carbonaceous 
materials — as charcoal or charred leather — and subject 
to heat until the piece has reached the desired uniform 
temperature, being careful that the part which is 
exposed to the direct heat of the fire does not get 
over-heated. 

Another method which is used when an article 
must be hard on all its surfaces is to cover the piece 
with a carbonaceous paste, consisting of the following 
ingredients : 

Pulverized charred leather 2 parts. 

Fine family flour . . 2 " 

Fine table salt 1 part. 

Mix thoroughly while in a dry state. Water is then 
added slowly to prevent lumps ; enough water may be 
added to make it of the desired consistency, which 
depends on the nature of the work and the length of 
time it must be exposed to the action of the fire. If 
the articles are small and will heat to the proper temp- 
erature for hardening in a few minutes, it should be of 
the consistency of varnish. If, however, the pieces are 
large and require considerable time for heating, it must 
be made thicker. 

Various substances are heated red hot in crucibles 
or iron dishes, and pieces to be hardened are heated in 
them. These exclude the air and so prevent oxidation 
and decarboniaation of the surface of the steel. Among 
the substances used are lead, tin, glass, cyanide of 
potassium, a mixture of salt and cyanide of potassium. 

Lead is heated in a crucible in a furnace of the 
forms shown in Figs. 15, 16. It furnishes a very excel- 

46 



Heating in molten lead. 

lent means of heating work which is hardened in large 
quantities. When making furnaces to heat lead red 
hot for use in hardening steel, some means should be 
provided for carrying off the fumes of the lead, as they 

are very injuri- 
ous to the work- 
man. They are 
especially hard to 
dispose of, as 
they are heavier 
than the atmos- 
pheric air ; conse- 
quently cannot 
be disposed of as 
readily by means 
of a ventilating 
shaft as other 
fumes. It is nec- 
essary to furnish 
a pipe connected 
with an exhaust 
fan. This pipe 
may be at the back of the furnace instead of over it, as 
is generally the case when gases or smoke are to be 
carried off. It should not be arranged in a manner 
that will cause the surface of the lead to become 
cooled by a current of air passing over it. 

If illuminating gas can be procured at a reasonable 
rate, it furnishes an ideal method of heating a crucible 
of lead. Furnaces burning illuminating gas can be pro- 
cured of a size and shape adapted to the work to be 
done. If, however, it is considered advisable to make 
a furnace for this purpose, one may be made which 




The Derry Collard Co. 
Figure 15. Lead hardening furnace. 



47 



Heating in molten lead. 

will give good satisfaction. It can be made to burn 
oil, coal, charcoal or coke. If oil is the fuel to be used, 
it is advisable to install a system especially for this 
method, and as circulars and full explanations can be 




The Derry Collard Co. 

Figure 16. Lead furnace for hardening. 



procured from manufacturers who make these outfits, 
it would not be wise to go into their details here. 

If it is considered advisable to make a furnace 
burning charcoal, hard coal or coke, the design shown 
in Fig. 17 may be used or changed to adapt it to 
these fuels. The outer shell may be made of cast 
iron, although it may be possible to procure an old 

48 



II 



o me- made 



lead heating apparatus. 



BACK HALF. TOP PLAT^ 




F.ICNT HALF 



boiler, which can 
usually be bought 
very cheaply. A 
piece the desired 
length may be cut 
from this, that an- 
swers the purpose 
very nicely. A round 
grate and the neces- 
sary frame to support 
it may be procured 
from a stove dealer. 
The form of erate 



[Willi Hill 








u 

o 






^o> n □ <>□□ 






P 













BOTTOM PLATE- 



SECTION 
4 LEGS \\i ROUND IRON 



Figure 17. Coal, coke or charcoal furnace for lead heating. 
49 



"Home-made" lead heating apparatus. 

used in the ordinary cylinder parlor stove will answer 
every purpose. The frame should be attached to the 
shell or blocked up from the bottom of the ash box, to 
allow the grate to be turned in dumping the contents of 
the furnace. The interior of the furnace may be made 
of circular fire brick, which may be supported by the 
slab which forms the base or bottom of the ash box and 
designated as the bottom plate. In case fire brick are 
used, the grate frame may be built into the brick work 
as shown. If, however, a stove lining of the desired 
size can be procured, the bricks need extend only up 
to the frame, the lining extending from the frame to 
the top of the shell. It is necessary to cut an opening 
in the ash box in the front of the shell. This should 
be covered with a swinging door, containing a sliding 
damper. This door is necessary in order to remove 
the ashes. 

A smoke pipe must be provided to carry off the 
smoke and gas from the fire. This should be con- 
nected with the shell at the top on the back side of the 
furnace. Over the top of the furnace must be placed 
a plate, having a hole in the center about one half inch 
larger than the size of the crucible to be used. This 
plate should be cast in two pieces, having more than 
one-half of the hole in the part that goes at the back. 
The smaller or front half may be moved forward, thus 
affording an opening to feed the coal to the fire. The 
object in having more than one-half the opening in the 
back part of the cover is to prevent the crucible from 
tipping over when the front plate is removed, when 
there is not sufficient coal in the furnace to support it. 
It is necessary to place a piece of fire brick in the 
center of the grate for the crucible to rest on in order 

5° 



Cyanide of potassium furnace. 



that the fire may be beneath it. The smoke pipe 
should be provided with a clamper, to enable the 
operator to properly control the fire. This form of 

furnace gives 
best satisfaction 
when hard coal 
is used as fuel. 

Red-hot cya- 
nide of potassium 
is used with ex- 
cellent results in 
heating- tools for 
hardening. It 
not only heats the 
steel uniformly, 
but, being lighter 
than steel, the 
latter sinks in the 
fluid, thus effect- 
ually excluding 
the air from the 
surface of the 
steel. It also has 
the effect of mak- 
ing the surface 
somewhat harder 
than it otherwise 
would be, without 
making the steel 
more brittle. 

It should be 
borne in mind 
that cyanide of 




Figure 18. Furnace for heating in 
cyanide of potassium. 



Heating cyanide by gas furnace. 

potassium is a violent poison, and great care should be 
exercised in its use. Not only is it poisonous when 
taken into the stomach, but the fumes are highly in- 
jurious to the workman if inhaled. However, if fur- 
naces are properly designed and set up, the fumes may 
be disposed of in a manner that does away with this 
trouble. 

In Fig. 1 8 is shown a form of furnace made es- 
pecially for use in heating in cyanide of potassium. 
The fuel used is illuminating gas, the products of 
combustion passing up the pipe E to the main pipe F 
which also conveys the fumes of the melted cyanide 
into the chimney or ventilating shaft. The burners 
enter the furnace at A and heat the crucible B, which 
contains the cyanide. A hood C, which is provided 
with a door D, keeps the fumes from entering the 
room as they are conveyed into the pipe F. The 
lighting holes G G are closed by the plugs shown 
when the fire is well under way. 

When a comparatively small number of small 
pieces are to be hardened, it is possible to heat the 
necessary amount of cyanide in a small iron dish in an 
ordinary forge. The pieces may be held in this until 
the desired effect has been accomplished, when they 
may be quenched. 

As the work heated in this manner is usually hung 
from the edge of the crucible by means of wire hooks, 
it is generally considered advisable to use a square 
crucible rather than a round one when work is done 
in large quantities. 

When a furnace is to be made for this purpose, the 
form represented in Figs. 19-20 will be found to give 
good results. This furnace burns hard coal. The cruci- 



"Home-made" cyanide furnace. 

ble which is made of cast iron is square in shape and 

hangs from the flange, 
which is cast around 
the upper edge. The 
top of the crucible is 
below the top of the 
back of the furnace. 
An opening into this 
allows the fumes to es- 
cape into the chimney. 
A quantity of salt 
is placed in a crucible 
and heated red hot. 
To this is added cya- 



Figures 19-20. A "home-made" 
cyanide heating furnace. 













^fF 


— 2> 


c 


1 










4a 


f 


O 





Crucible 



9////////////////s/s///s////>. 



nide of potas- 
s i Vl m until 
the steel 
heated in 
it shows 
the proper 
amount of 
hardness. 
This method 
is used by 
manufactur- 
ers of taps 
and similar 
tools, who 
claim excellent results by its use. The same general 

53 



Fire Box 



Grate 



Ash Box 



Where furnaces should be located. 

remarks apply to this method as to heating in cyanide 
of potassium. 

Glass heated in a crucible until it is red-hot is the 
means used by some watch makers to heat the hair 
springs of the watches. It is claimed that the nature 
of steel heated in this manner will not change in the 
least. 

Very little attention is paid in most shops to the 
location of the forge or furnace used in heating steel ; 
generally any out-of-the-way place is selected. If 
there is any portion of the shop that cannot be utilized 
for anything else, it is given up to this purpose. 

The fire for heating steel should receive more con- 
sideration, so far as location is concerned, than almost 
any other part of the equipment. It should never be 
located where the direct rays of the sun or any strong 
light can shine in it, or in the operator's eyes, for un- 
even results will surely follow. It should never be 
located in or near a window, neither should the roof be 
constructed with skylights which allow any of the 
sun's rays or any strong light to enter the portion of 
the room where the furnace is located. 

An ideal place for the location of a furnace used in 
heating steel for hardening, is in a room so constructed 
that no rays of sunshine or direct light can enter it. 

It is extremely important that due consideration 
is given the subject of ventilation. Some means 
should be provided whereby pure air can be freely 
supplied without creating drafts, which would cause 
the operator, who is perspiring freely, to take cold. 
The room should be so located that it will not be damp, 
or the health of the workman would be hazarded. 

Too often in the past the precautions noted have 

54 



Heating tool steel. 

received very little consideration, because those in 
charge did not realize the importance of a properly 
equipped or located room in which to do this class of 
work. 



Heating Tool Steel 



CO 

Tool steel is very sensitive to the action of heat. 
A slight difference in temperature after a piece has 
reached the proper hardening heat will be noticeable 
in the grain of the steel. When heating for hardening, 
the lowest possible heat that will give the desired 
result should be used. The amount of heat necessary 
to produce this result depends on the make of the steel, 
the percentage of carbon it contains, the percentage of 
other hardening elements that may be in the steel, 
the size of the piece, and the use to which it is to be put 
when hardened — all these must be taken into con- 
sideration. A steel low in carbon requires a higher 
heat than a piece of high carbon steel in order that it 
may be as hard. A small tool does not require as much 
heat as a larger one of the same general outline. A 
tool with teeth or other projections will harden at a 
lower heat than a solid piece of the same eize made 
from the same bar of steel. There is a proper heat at 
which a piece of steel should be hardened in order to 
produce the best results, but this heat varies, as pre- 
viously explained. 

If two milling machine cutters were made from 

55 



Refining heat, and what it means. 

two different makes of steel the writer has in mind, 
and were heated in a manner that would give excellent 
results in the case of one, the other would not harden 
satisfactorily. Now, were the operator to heat both to 
the proper hardening heat for the other make, the first 
one mentioned would be unfitted to do what was 
expected of it. Either make of steel would give good 
results if heated to its proper heat. 

The commonly used expression of degrees of heat 
which tool steel should receive is a cherry red. The 
writer cannot dispute the appropriateness of this term, 
but cherry red is a varying color when applied to the 
hardening heat of tool steel, and also when applied to 
cherries. Mr. Metcalf, in his work on steel, styles 
this heat as the refining heat, and this seems to express 
the idea nicely. 

Steel should be heated to a temperature that, when 
hardened and broken, the fracture will show the grain 
to be the finest possible, and the steel will be hard. 
Now, if we heat a piece from the same bar a trifle 
hotter and break it, the fracture will show a coarser 
grain. The hotter the piece is heated, the coarser the 
grain becomes ; and the coarser it is, the more brittle 
the steel is. While, to be sure, steel heated a trifle 
above the refining heat will be somewhat harder than if 
heated to the refining heat, yet the brittleness more 
than offsets the extra hardness ; and if it is to be used, 
it will be found necessary to draw the temper in order 
to reduce the brittleness to a point where it is practical 
to use the tool. 

After taking the necessary means to reduce the 
brittleness as described, an examination of the tool 
will reveal the fact that in drawing the temper we have 

56 



The use of test pieces. 

softened the piece to an extent that it is not as hard as 
the piece hardened at the refining heat. Neither will it 
do anywhere near the amount of work, as the grain is 
open and when the pressure is applied in the operation 
of cutting, the surface caves in because of the open 
grain. The surface has not the backing it would have, 
were the grain close or fine. 

A method which the writer has used in his experi- 
ments and also in demonstrating the effect of heat on 
the grain of steel is to take six pieces of steel that can 



The Derry Collard Cw 

Figure 21. Test pieces. 

be readily broken. Cut the required number from a 
bar i inch to i^ inches diameter, having the pieces 
about yV of an inch thick. Now heat the pieces one at 
a time in a furnace so situated that no rays of the sun 
or any strong light can shine either into the fire or into 
the eyes of the operator. It is advisable to have the 
furnace located in a room that can be darkened so that 
it is neither light nor extremely dark, but it must be 
uniform throughout the experiment. Now heat one 
piece until it shows somewhat red, yet a certain black 
is discernible in the center of the piece. Dip into ths 
bath and work it around well ; leave until cold. Now 

57 



What test pieces will show. 

heat another piece until it shows the lowest red pos- 
sible throughout with no trace of black. Heat the 
third piece a trifle hotter, and continue to heat each 
piece hotter than the preceding one until they are all 
hardened, heating number 6 to what is familiarly 
termed a white heat. 

Previous to heating, each piece should be stamped 
in two places, as shown in Fig. 21, in order that the 
pieces may be broken across the center, as indicated by 
the dotted lines, and yet the halves of the same piece 
be easily recognized. When heating, commence with 
the piece marked 1, and heat consecutively. After 
hardening them all at the different heats, dry thoroughly 
in saw dust or by any means whereby the surface may 
be made perfectly dry, after which they may be broken. 
This can be done by screwing the piece in the jaws of 
a vise, putting about one half of it below the tops of 
the jaws. With a hammer the upper part may be 
broken off, being careful that the piece does not fly and 
strike so as to stain the walls of the fracture ; or the 
part projecting above the vise may be caught between 
the jaws of a monkey wrench and the piece broken. 

An examination of the piece marked Fig. 2 2 will 
show it to be somewhat hardened. The grain will not 
be especially fine and will have a peculiar appearance. 
No. 2 will be very hard and the grain will be very fine. 
It will break with very ragged walls, as shown. No. 3 
will also be very hard and the grain not as fine as No. 
2. The grain of No. 4 will be coarser than No. 3. 
No. 5 will be coarser than No. 4, while the grain of 
No. 6 will be extremely coarse and the steel unfitted 
for anything but the scrap heap. 

It will pay any man who is desirous of learning to 

58 



r~ ■ 



;:". ' , TT" ; 








*$&&&&& 




be 



Temperatures for different steels. 

harden steel properly to try this experiment. The steel 
will eost him but a few cents, and it need take but a 
short time to heat it ; but the knowledge gained of the 
action of heat on tool steel will be of inestimable value 
to him, as he can readily see the effects of proper and 
improper heating on the structure and strength of steel. 

If the operator notes carefully the heats, he will 
be surprised at the difference in the amount of force 
necessary to break a piece of steel hardened at the 
refining heat and one heated slightly above this tem- 
perature, which, in fact, is hardly discernible to the eye 
in the light of an ordinary blacksmith's shop. The 
difference in the strength of a piece hardened at the 
refining heat and one heated to a. full red is especially 
noticeable. In the former case it seems almost impos- 
sible to break it by a blow of a hammer, and it seldom 
can be broken across the center, so great is the adhesion 
between the molecules that make up the piece of steel, 
while in the case of a piece heated to a full red, the 
piece may be broken easily, as compared with the 
other. When one takes into consideration the fact that 
the ordinary workman heats steel when hardening to a 
full red oftener than to the refining heat, it is wonder- 
ful that the results obtained are as satisfactory as they 
are. 

As stated, the temperature to which a piece of 
steel must be heated in order to refine it, depends on 
the composition of the steel. Tests of different steels 
have led authorities on this subject to the conclusion 
that it is necessary to heat a piece of steel to a tem- 
perature between 8oo° and 1200 Fahr. in order that it 
may harden when plunged in a cooling bath. Jaroli- 
neck places the temperature at 93 2 F. (500 C.) as 

59 



The uniform heating of steel. 

determined by experiments made by him, while other 
authorities claim best results when the steel was heated 
to 1200 F. .(about 650 C). As this difference (268 F.) 
involves a wide range of heat, it is evident that steels 
containing different percentages of carbon were used 
in the various tests. 

If a piece of steel be heated to the refining heat and 
then quenched as soon as the heat is uniform through- 
out the piece, the steel is in the best condition possible 
for most uses. It should be quenched as soon as it is 
uniformly heated to the proper temperature. If sub- 
jected to heat after it reaches this temperature, it will 
become somewhat hotter. In fact, it has been ascer- 
tained by experiment that after steel is heated to a low 
red the temperature may be raised, and the difference 
in the heat not be discernible to the eye. For this 
reason it is advisable, if best results are desired, to 
quench as soo?i as the desired wiiform heat is attained. 

It is also important that steel should be heated 
uniformly. If a square block be heated so that the 
center is of the proper heat and the ends and corners 
are hotter, strains are set up in the piece, and it is very 
liable to crack when hardened. This also applies to a 
piece of any shape. While it is extremely necessary 
that the operator observe the greatest possible care in 
regard to the quantity of heat given steel, yet it does 
not harm steel as much to heat it a trifle too hot as it 
does to heat it unevenly, for while the higher heat un- 
fits it for doing the maximum amount of work possible, 
the uneven heat is very liable to cause it to crack when 
hardened. 

A piece of steel should not be heated faster than is 
possible to maintain a uniform heat. By this is meant 

60 



The condition of the grain of steel. 

the heating should not be forced so that the outside is 
red hot while the center is black because in all prob- 
ability the furnace would be so hot that the outside of 
the article would keep growing hotter while the center 
was getting to the desired heat. The result would be 
an uneven heat. Neither should a piece of steel be 
any longer in heating than is necessary, because after it 
is red hot, it will, if exposed to the action of the air, 
become somewhat decarbonized on the surface, thus 
materially affecting the steel. Tool steel should be 
heated as fast as it will take heat, and no faster. A 
piece should not be forced by heating the furnace to a 
temperature that will affect the surface while the heat 
is equalizing. Steel should never be heated too hot, 
and allowed to cool to what is considered the proper 
heat, and then hardened, as the grain will be as coarse 
as if dipped at the high heat. 

The grain of steel remains in the condition the 
highest heat received leaves it, until it is reheated, 
when it is adjusted to that heat. The condition of the 
grain of the steel is an unvarying guide as to the 
amount of heat it received the last time it was heated. 
For instance, a piece of steel is heated to the tempera- 
ture of the piece marked 4 Fig. 22 in our experiment. 
Now, take one of the broken pieces and reheat it to a 
temperature given the piece marked 2, which was the 
refining heat. Break this piece. An examination will 
reveal the fact that the grain has the same structure as 
the piece marked 2, thus proving that the grain of steel 
conforms to the last heat given it. This does not 
necessarily prove that a piece of steel is capable of 
doing the amount of work after it has been heated 
hotter than it should have been, and then reheated to a 

61 



Harden on a "rising heat." 

lower heat, thus closing the pores ; but it is better than 
if in the condition the high heat would leave it. 

Steel should always be hardened on what is known 
as a "rising" heat, never on a "falling" heat, is the 
advice an old hardener gave the writer when a boy, 
learning his trade, and he has found it true. It also 
agrees with the advice of most writers on this subject. 
It is quite necessary, in order to get uniform results, to 
move the articles around in the furnace and turn them 
over occasionally. When round (cylindrical) pieces of 
steel, having no teeth, projections, or other irregulari- 
ties on its surface, are being heated for hardening, it 
is necessary to turn them occasionally, as, if left in one 
position without turning, until it is red hot, no matter 
how uniform the heat may be, it will, in all probability, 
have a soft line the entire length of the top side as it 
lay in the fire. It will also be found by experiment 
that round pieces are more liable to crack from uneven 
heating than pieces of almost any other shape ; neither 
will they safely stand as high a degree of heat as some 
pieces, on account of their shape, which makes them 
offer greater resistance to a change of form. 

If possible, when heating articles having heavy 
and light sections adjoining each other, as shown in 
Fig. 23, heat the heavy portion first, then the lighter 
one; but if this is not possible, have a slow fire, in 
order that the light part may not be overheated before 
the heavy one is to the required heat. The muffle 
furnace furnishes a very satisfactory method of heating- 
steel, because the products of combustion cannot come 
in contact with the steel, and oxidation from the action 
of the air is done away with or reduced to the minimum. 
If it is not possible to use a furnace of this description, 

62 



Figure 23. 



The Deny Collar,! (. 

A piece for a slow fire. 



When coals should not he used. 

very good results may be obtained by enclosing the 
article in a piece of pipe or tube and heating in an open 
fire, because in this case the steel is not exposed to the 
action of the fire. It is necessary to turn the work 
over occasionally in order to get a uniform heat. 

It is never advisable to use any kind of fire where 

the air from the blast 
can strike the piece be- 
ing heated, or it will 
crack in innumerable 
places. The steel will 
look as though it were 
full of hairs. For this 
reason, if obliged to use 
a blacksmith's forge, build a fire high enough to do 
away with any tendency of this trouble. A fire of old 
coals should not be used if the article to be heated is of 
any size, as the goodness is burned out of the coal, 
and it will be found necessary to use a strong blast in 
order to have a fire hot enough to heat the piece.. 
As a consequence, the air strikes the piece with the 
result mentioned. 

Steel should not be heated in a manner that leaves 
one side exposed to the air, or the exposed side will 
become oxidized to a considerable extent, and as the 
piece is turned in the fire the whole surface becomes 
oxidized and resembles a piece of burnt steel. The 
surface is not of any use, as the carbon is burned out, 
and it cannot be hardened. Some makes of steel give 
off their surface carbon very readily if exposed to the 
air when red hot. If a tool made from one of these 
steels be heated in a manner that allows the air to come 
in contact with it, the outside becomes decarbonized. 



63 



The indifference of some hardeners. 

and consequently is soft, while the metal underneath 
the surface is extremely hard. Now, this might not be 
harmful in the case of a tool whose outer surface was 
to be ground away, but if the surface of a tap, formed 
mill or similar tool becomes decarbonized, it is practi- 
cally useless. Now, if these same tools had been 
heated in a muffle furnace or in a piece of pipe in the 
open fire, removed from the action of the fire and the 
air, the result would have been that the tool would 
have given excellent satisfaction. While all makes of 
steel are not so sensitive to the action of the fire and 
air when they are red hot, yet any steel gives better 
results if it is removed from their action while in this 
condition. 

A man experienced in the effects of heat on steel 
is surprised at the apparent indifference of some hard- 
eners when heating steel. A tool hardened properly 
and tested for strength in a testing machine will be 
found very much stronger than if heated a trifle hotter. 
When we consider that hardness, toughness and close- 
ness of grain are the qualities desired in a cutting tool, 
we realize that there is nothing gained by heating tool 
steel above the refining heat for most work. Steel 
quenched at this heat is very hard, tough, and the grain 
is the finest possible. Now, every degree of heat which 
it receives above this point unfits it for doing the 
maximum amount of work possible, because it causes 
the steel to be brittle and makes the grain coarse. 

The writer has made exhaustive experiments in 
regard to the effects of heat on the strength of steel, 
and assures the reader that a piece of steel hardened at 
the refining heat requires a much greater force to 
break it than one heated to a full red. Knowing this, 

6 4 



Reheating to remove strains. 

the reader can judge how much heavier cuts can be 
taken with a tool properly heated than with one heated 
too hot, as the steel is made brittle, and in this condi- 
tion is more liable to chip or flake off under pressure. 
The grain being coarse does not present a dense body, 
but the internal structure has a honeycomb appear- 
ance ; consequently when pressure is applied the surface 
caves in, because it does not have the backing it would 
if the grain were compact. 



Reheating to Remove Strains. 

As steel heated red-hot and cooled quickly con- 
tracts, and as the outer surface hardens and becomes 
rigid before the interior of the piece has ceased con- 
tracting and altering its form and the position of its 
molecules, the molecules that make up the interior of 
the piece cannot assume the exact positions they 
should ; consequently, strains are set up. Now, if the 
outer portion of the article is sufficiently strong to 
resist the tendency of the interior of the piece to alter 
its form, it may not crack or it may resist the strain 
for a considerable length of time. But for some cause 
a certain portion of the exterior of the piece becomes 
weakened, or the conditions are such that the outside 
can not longer resist the internal strain, and the piece 
is cracked, or it may burst. Many times large, heavy 
pieces of steel will burst with a report as loud as a gun, 
and pieces of the steel will be carried for some distance 
by the force exerted. 

Now, in order to avoid this tendency, it is neces- 

65 



Pliability of hardened steel. 

sary to reheat the piece as soon as it is taken from the 
hardening bath, to a temperature that allows the vari- 
ous portions of the piece to conform to one another. 
A piece of hardened steel becomes pliable to a degree 
when heated, the amount of pliability depending on 
the temperature to which the piece is heated. This is 
illustrated elsewhere in the case of articles crooked in 
hardening, which are straightened after heating to a 
certain temperature. After cooling they remain the 
shape given, but were we to attempt to spring them as 
much when cold, they would certainly break. 

It is advisable, after taking a piece of hardened 
steel from the bath, to hold it over a fire or in some man- 
ner subject it to heat, in order that it may become 
pliable enough to remove the tendency to crack from 
internal strains. 

The method pursued in removing the strains 
varies. If an open fire is at hand, the piece may be 
held over this until heated to the proper temperature. 
It should be constantly turned, in order to insure uni- 
form results. When pieces are hardened in large 
quantities, this is a very expensive practice. In such 
cases, it is advisable to have a tank of oil, which is 
kept at the desired temperature, this being gauged by 
means of a thermometer. 

A very satisfactory method, and one used by the 
writer for many years, consists in using a tank of 
water, the contents of which are kept at the boiling 
point (2 1 2°). When a piece of hardened steel is 
removed from the bath, it is immediately dropped in 
the boiling water. The tank has a catch pan to receive 
the work, as shown in Fig. 24. A steam pipe is con- 
nected with the tank in order to keep the water at the 

66 



The removal of internal strains. 

desired temperature. It is, of course, necessary to 

provide an overflow pipe, as represented. 

When it is not considered advisable to procure a 

tank, as represented, a kettle of water may be placed 

over a fire and brought to the boiling point and used 

as described. 

When it is thought to be advisable to remove the 

tendency to crack 
from internal 
strains and draw 
the temper at the 
same time, it may 
be done by heating 
a kettle of oil to 
the desired tem- 
perature, gauging 
the heat by a ther- 
mometer. The 
pieces, as they are 
taken from the 
hardening bath, 
may be dropped in 
this and left long 
enough to insure 
uniform heating. 



Perforated Catch Pan 



ty/////////s;;/////;///////////y/////////y//M. 




The Derry Collard Co. 



Figure 24. Tank, of boiling water 
for removing internal strains. 



Should it be considered advisable to heat articles 
of irregular shape, having heavy and light portions 
adjoining each other, it would not be advisable to sud- 
denly immerse them in liquid heated to 300 , 400 or 500 
Fahr., as the unequal expansion might cause the pieces 
to crack where the heavy and light portions joined. 
In such cases it is sometimes considered advisable to 
place them in a kettle of boiling water first, removing 



67 



Forging troubles. 

them from time to time and placing in the kettle of 
oil, heated to the temperature to which the pieces must 
be heated in drawing temper; or two kettles of oil, 
heated to different temperatures, are sometimes used, 
the first being kept at 250 or as as near that as possi- 
ble, the other being the desired temperature. When 
the pieces are removed from the first kettle and placed 
in the second, it, of course, reduces the temperature of 
the oil, but it gradually rises to the desired point when 
the articles are removed. 



Forging. 




CO 

It is not the writer's intention to devote much 
space to explanation of the method in which steel 
should be forged for the various cutting tools. In 
order to do the subject justice, it would be necessary 
to devote more space than can be spared, but the forg- 
ing and hardening of a tool are so closely identified, it 
seems necessary to briefly consider the subject. 

Many tools are rendered unfit for use by the treat- 
ment they receive in the forge shop, and as it is the 
custom in many shops to have the forging done by one 
man, and the hardening by another, a great amount of 
trouble is experienced, because each tries to lay any 
trouble that comes from the hardened product to the 
other. 

Heating is the most important of the operations to 
which it is necessary to subject steel, whether it be for 
forging, annealing or hardening. 

68 



Superiority of hammered steel. 

Unless steel is uniformly heated throughout, vio- 
lent strains are set up; when the piece is hardened 
these manifest themselves. If the steel is not heated 
uniformly throughout the mass, it cannot flow evenly 
under the blows of the hammer, consequently the grain 
is not closed in a uniform manner. 

While it is necessary, in order to get satisfactory 
results, to heat steel hot enough to make it plastic, in 
order that it may be hammered to shape, care should 
be exercised that it is not overheated, or the grain will 
be opened to an extent that it can not be closed by any 
means at hand in the ordinary forge shop. 

If a large piece of steel requiring considerable 
change in size is to be forged, and means are at hand 
to forge it with heavy blows, it can safely be given a 
higher heat than a smaller article which does not require 
much change of size or form. 

If tool steel is hammered carefully, with heavy 
blows while it is the hottest, and then with lighter, 
more rapid blows as it cools, the grain will be closed 
and become very fine. 

When the temperature is reduced to a low red, 
care should be exercised, for when traces of black begin 
to show through the red, it is dangerous to then give it 
any heavy blows, as they would crush the grain. 

By actual test it has been proven time and again 
that steel, which has been properly hammered, is super- 
ior to the same steel as it comes from the steel mill, 
but unless the work is done by an intelligent smith, 
who understands the effect of heat on the structure of 
steel, the forging will have the opposite effect to the 
one desired. 

Many steel manufacturers advocate the purchase 
6 9 



"Hammer refined" steel. 

of steel in bars of the desired size, and do not advise 
forging, claiming best results if the article is machined 
to size and shape. The reason for this is, that there 
are many careless, ignorant workers of steel in the 
various blacksmith shops — men who either do not know 
the effects of improper methods of heating and ham- 
mering, or knowing, do not care. As a consequence, 
a great quantity of steel is annually rendered unfit for 
doing the work it might do were it treated properly. 

For this reason it is advisable to machine a piece 
of steel to shape, rather than to have it forged by any 
but a skillful smith. Yet the fact remains that a piece 
of steel heated and hammered properly will do more 
work than a tool of the same description cut from the 
same bar and machined to shape, even if it is hardened 
in exactly the same manner. 

A piece of steel properly forged is known by tool 
makers as "hammer refined" steel, and is highly valued 
by them for tools which are expected to do extra hard 
work. Tool steel is furnished in bars, blanks or forg- 
ings of almost any desired shape. 

The smith should bear in mind that heats which 
are too high open the grain, thereby weakening the 
steel and making it incapable of doing the largest 
amount of work possible. If steel is hammered when 
too cold, the grain is crushed, causing it to crack when 
hardened ; or if it does not crack, the cutting edges will 
flake off when in use. If the steel is unevenly heated, 
that is, the outside heated hotter than the inside, the 
outside portion being softer will respond to the action 
of the hammer more readily than the less plastic in- 
terior, and the outer portion will be torn apart. 

Too often it happens that when the smith is rushed 

70 



The object of annealing steel. 

with work he will attempt to heat a large bar of iron 
for forging, and while that is heating, will try to forge 
or harden tools .someone is waiting for. The spirit of 
willingness to accommodate is commendable, but a 
decided lack of judgment is noticeable, because a fire 
suitable for heating a piece of iron to a forging heat 
is in no ways adapted to heating a tool either for forg- 
ing or hardening. 

Then again, if the smith is heating iron to its 
proper forging heat, his eyes are in no condition to 
properly discern the correct heat to give a piece of tool 
steel. 



Annealing. 




CO 



According to the generally accepted definition of 
the term, the object of annealing steel is to soften it in 
order that it may be machined at the minimum cost of 
labor and tools. 

The method pursued in annealing steel depends, as 
a rule, on the facilities which the shop possesses for 
doing this class of work. A piece may be softened 
somewhat by heating red-hot and laying it to one side 
to cool in the air, provided it is not placed on any sub- 
stance that will chill it. Neither should it be placed 
where any current of air can strike it, or it will cool 
too quickly to become soft. In fact, it would very 
likely be harder than if worked without attempting to 
anneal it. 

The young hardener should understand that a 

71 



How annealing is best done. 

piece of steel is hardened by heating red-hot and cool- 
ing quickly ; the more rapid the process of cooling, the 
harder the steel will be. Annealing has the opposite 
effect. Steel is annealed by heating red-hot and cool- 
ing slowly; the greater the amount of time consumed 
in the cooling operation, the softer the steel will be, 
everything else being equal. Now, it is evident that, 
if a piece of steel be heated to a red and placed on an 
anvil or other piece of cold metal or thrown on the 
floor, the portion laying on the cold substance will 
chill and the process of hardening, rather than anneal- 
ing, will be carried on. 

The same is true if a piece is placed where a cur- 
rent of air can strike it, even if it is warm air, as it will 
be cooler than the steel and the heat in the steel will be 
taken up by the air. Thus, the operation will be the 
opposite of the one desired. 

It is the custom in many shops to anneal steel by 
heating and putting it in a box of ashes or lime. Now, 
this may be advisable, or it may not be, according to the 
condition of the contents of the annealing box. If the 
room in which the box is kept is damp, the ashes or 
lime, especially the lime, will absorb enough moisture 
to chill the piece of red-hot steel, particularly if it be 
small or thin. So we have again a piece of steel 
hardened to a degree, instead of annealed. When steel 
is to be annealed by this process, it is advisable to heat 
a piece of iron or scrap steel and bury it in the ashes 
or lime, leaving it there until the piece to be annealed 
is properly heated, when it may be removed, and the 
piece to be annealed put in its place. The ashes or 
lime being heated, and every trace of moisture removed, 
the process of cooling will be slow and the results 

7 a 



Methods of annealing. 

satisfactory. A box of lime furnishes an excellent 
method of annealing steel, if the precaution mentioned 
is observed. 

A very satisfactory method of annealing, which has 
been used by the writer many times where there was 
only one or two pieces to anneal at a time, consists in 
taking an iron box, putting two or three inches of ashes 
in the bottom and laying a piece of board a trifle larger 
than the work on them. Heat the pieces to be an- 
nealed to the proper 
degree, lay them on 
the board, lay an- 
other piece of board 
on top of them, and 
£j work |r=: =Jj fill the box with 

ashes, as shown in 
Fig. 25. The pieces 
of board will 
Figure 25. smoulder and keep 

the steel hot for a 

An iron box filled with ashes for annealing ] on p; time The pro- 

between boards. r ... .-., 

cess of cooling will 
be very slow. 
There is a method of annealing practiced in some 
shops which, while it has many advocates, cannot be 
recommended by the writer, except as a means of an- 
nealing a piece of steel that is wanted right away. It 
is known as cold water annealing. This method has 
advocates among old hardeners, some of whom get 
excellent results; but as a method of annealing to be 
practiced by one who is not thoroughly familiar with 
the action of fire and water on tool steel, its use is 
hardly to be advocated. The steel is heated to a red 

73 



Annealing in gas furnace. 

and allowed to cool in the air where no current of air 
can strike it, held in a dark place, and when every 
trace of red has disappeared, plunged in water and left 
until cold. The steel will be softer if plunged into 
soapy water or oil. 

This answers in an emergency, but on account of 
the ends cooling faster than the center and the smaller 
portions cooling more rapidly than the larger ones, it is 
apparent that the piece of steel must be of an uneven 
temperature throughout when cooled. 

The method practiced in many shops of heating a 
piece of steel in a furnace to the proper annealing heat, 
using gas, oil or gasoline as fuel, then shutting off the 
supply and allowing the work to cool down with the 
furnace, is attended with varying results. While many 
mechanics advocate this method and claim excellent 
results, and it has been used by the writer to his entire 
satisfaction, yet several cases have come to his notice 
of late where parties had annealed this way with re- 
sults that were far from satisfactory. Investigation 
showed that in heating the steel the furnace had been 
forced in order to heat the piece quickly, and as the 
steel was heated by radiation it was necessary that the 
walls of the furnace should be hotter than the piece of 
steel being heated. 

When the steel had apparently reached the proper 
heat, the supply of fuel was shut off, but the inside 
walls of the furnace, being much hotter than the work, 
imparted heat to the steel after the fire was put out, 
with the result that the steel was overheated and 
injured, and in some cases entirely unfitted for the use 
it was intended for. A steel maker of national reputa- 
tion says that "many thousand dollars' worth of steel are 

74 



Annealing in iron boxes. 

ruined annually in this way, and it is in every way about 
the worst method of annealing that was ever devised.'' 

Knowing the vast amount of trouble caused by 
attempts of various parties to use this method, the 
writer feels it his duty to condemn a method he has 
used successfully under favorable circumstances, be- 
cause all mechanics are not so favorably situated. 
They do not use the same care in heating steel, especi- 
ally when it is nearly to the proper temperature, but 
insist on forcing it, not only to the detriment of the 
edges and corners, which are bound to heat faster than 
the center. In this way the whole piece is ruined or 
injured, because the furnace is hotter than the steel, 
and when the fire was extinguished, the furnace was 
closed and there was no means of looking in. to deter- 
mine the amount of heat the steel was receiving, but 
the results showed it had been heated too much for its 
good. 

Now, if a comparatively small furnace is used, or 
one having light walls, which will not hold the heat for 
a very great length of time, the danger of over-heating 
by radiation after the fire is extinguished is reduced to 
the minimum. But on the contrary, if the furnace has 
heavy walls of masonry, capable of retaining the 
excessive heat for a considerable length of time, the 
liability of overheating is very great. 

A method of annealing that gives universal satis- 
faction when properly done, and is used in many shops, 
consists in packing the steel in iron boxes and filling 
the spaces between the pieces of steel with powdered 
charcoal. It is necessary when annealing by this 
method to place one or two inches of charcoal in the 
bottom of the box before putting in any steel. Do not 

75 



Box method of annealin 



g- 



allow the pieces of steel to come within one-half inch 
of each other in the box, or within one inch of the box 
at any point. 

When nearly full, fill the balance of the space with 
charcoal, put on the cover and seal the edges with fire- 
clay. The reason for keeping the steel from coming 
into contact with the box is that the iron, especially 



The Derry Collard Co. 



1 1 C^J I 



□ EH LZJ 



Z^3 EJ 

czn □ 



LZl 



,^~7 ; ; ' r-^iJ 



Figure 26. Iron box for annealing. 



cast iron, has a great affinity for carbon, and will, 
when they are both red hot, extract it from the steel, 
leaving the latter somewhat decarbonized at the point 
of contact. 

In order to be able to determine when the contents 
of the box are heated to the proper degree, several % 
inch holes should be drilled through the center of the 
cover and a ■(§ wire run down through each of these 

76 



Process of annealing in boxes. 

to the bottom of the box, as shown in the sectional 
view, Fig. 26. 

When the box has been in the fire long enough, 
according to the judgment of the operator, to heat 
through, draw one of these wires by means of a pair of 
long-handled tongs, or by a pair of ordinary length, 
slipping a piece of gas pipe on each leg to give the re- 
quired length. If the wire drawn shows hot the entire 
length, the operator may rest assured that the steel is 
of the same temperature, because the wire was run 
down between the pieces at the center of the box. If 
the wire did not show red-hot, wait a while and draw 
another. When a wire is drawn that shows the proper 
degree of heat, the box should be left long enough to 
insure its being heated uniformily throughout, then the 
fire may be extinguished. If the walls of the furnace 
are much hotter than the boxes, the door may be left 
open until they are somewhat cool. If the furnace 
shows a disposition to heat the boxes too hot with the 
door open, they may be removed for a few minutes 
until the furnace is somewhat cooler, when the boxes 
may be returned to the furnace, the door closed and 
the work allowed to cool slowly. 

A method that insures excellent results is to plan, 
if possible, to empty one furnace of work to be hard- 
ened some little time before the work being annealed 
is sufficiently heated. Keep the first furnace closed to 
retain the heat as much as possible, so that it will pass 
the stage where it is liable to overheat the articles, and 
it will commence to cool down somewhat. When the 
work being heated for annealing has been subjected to 
the heat a sufficient length of time, the boxes may be 
removed from the furnace they were heated in and 

77 



Blocking out work for annealing. 




Figure 27. 



An irregular milling 
cutter. 



placed in the first furnace. All clanger of heating too 
hot from radiation is done away with. This method 
cannot, of course, be prac- 
ticed if there is but one 
furnace. 

While it is generally un- 
derstood that the object of 
annealing steel is to make it 
soft enough to work to ad- 
vantage, yet from the hard- 
ener's standpoint annealing 
has another and more import- 
ant office than simply to 
make steel workable. 

A piece of steel as it comes from the steel mill or 
forge shop is very apt to show a difference of grain in 
various parts of the piece, due to uneven heating and 
an unequal closing of the pores in the process of rolling 

or hammering; consequently 
there exists in the piece internal 
strains. In order to overcome 
the effect of these internal 
strains, which must manifest 
themselves when the steel is 
hardened, the work should be 
blocked out somewhere near the 
shape and annealed. If the 
piece is a milling machine cut- 
ter, punch press die, or similar 
tool, having one or more holes 
through it, the holes should be made somewhat smaller 
than finish size before annealing to remove strains. If 
it is a milling machine cutter of irregular contour, as 

78 



Figure 28. Irregular milling 

cutter blocked out for 

annealing. 



How to straighten work after springing. 

shown in Fig. 27, it should be blocked out as repre- 
sented in Fig. 28. The benefit gained in pursuing this 
course is that it is heated for annealing under as 
nearly as possible the same conditions, so far as shape 
is concerned, as when heated for hardening; conse- 
quently the tendency to change shape will be overcome 
in the annealing. 

Long pieces of steel that are to be hardened will 
give much better results if roughed out — that is, all 
scale and outside surface removed by planing or turn- 
ing — then thoroughly annealed. Should the piece 
spring when annealing do not straighten when cold, as 
it is almost sure to spring when hardened. If it is not 
sufficiently large to turn out without straightening, it 
should be heated red-hot and straightened. The hard- 
ener is blamed many times because a costly reamer or 
broach or similar tool is crooked in hardening, when in 
reality the blame rests with the man who turned or 
planed it to size. 

After it was annealed he tested it in the lathe, and 
finding it running out somewhat he takes it to an iron 
block or an anvil, and commences to hammer. He fin- 
ally gets it fairly straight, and feels quite proud of his 
job. He doesn't like to see a man machine a piece of 
steel that is crooked even if it will finish out, when a 
few strokes of a hammer will fix it all right. 

He has, by means of hammering, set up a system 
of internal strains much more serious than the ones 
removed by the process of annealing. He commences 
to machine the piece. Every time he goes below the 
effects of a hammer mark, the particles of the piece of 
steel "goes " or moves in some direction at this point, 
and it is necessary to repeat the operation of hammer 

79 



Shifting the blame. 

persuasion again, with the effect that by the time the 
article is ready to harden, it is in no condition to be 
hardened. It is either crooked in all directions, or it 
is only waiting for the fire to relieve it and allow it to 
go where it will. When the hardener gets through 
with it, it looks like a cow's horn, and of course the 
hardener is blamed. 

If he happens to be a man without any machine 
shop experience, or does not understand the nature and 
peculiarities of steel, he does not know where to place 
the blame, and perhaps it wouldn't do any good if he 
did. 

He, of course, isn't going to shoulder it, so the 
fault is laid to the steel, and, in consequence, if the 
trouble continues, another make of steel is bought be- 
cause the man in charge does not know or cannot spend 
time to locate the trouble. It cannot be the fault of 
the man in the shop, they say ; it must be the steel ; or 
they decide it must be the hardener, because some 
other concern with whom they are acquainted use this 
same steel and have no trouble, so the hardener has to 
stand the blame. 

A successful business man is quoted as saying: 
"If I were to drive a mule team, I would study the 
nature of mules." A man to be a successful hardener 
must study the nature of steel. He must know what 
steel is liable to do under certain conditions, and how 
to avoid undesirable results. No matter whether it re- 
lates to his department or some other department, he 
should know that it is possible for the tool maker to 
treat the steel in such a manner that results anything 
but satisfactory must follow when it is hardened. He 
should also understand that he may make the steel un- 

80 



The wrong way to anneal. 

fit for use by overheating when annealing, or he may 

not heat it uniformly throughout, and consequently 
does not remove the tendency to spring - from internal 
strains. If a satisfactory steel is furnished, the hard- 
ener should never blame the steel for bad results which 
are caused by his ignorance or carelessness, because he 
may be furnished with an undesirable steel next time. 
And in time those over him in authority will tire of 
complaints about a steel that another concern is satisfied 
with. 

A method of annealing steel which the writer has 
seen practiced in some shops, but which should never 
be used when annealing tool steel, is to pack the articles 
in a box with cast iron dust or chips. Now this method 
works nicely when annealing forgings or other pieces 
of machinery steel which were hard and show glassy 
spots and cannot be softened by the ordinary processes 
of annealing. The cast iron seems to have an affinity 
for the impurities liable to be present in the low grade 
steels, and the result is very soft and easily worked 
pieces. But if the method is applied to tool steel the 
carbon is extracted to an extent which is highly injur- 
ious to it. To be sure, tool steel can be annealed very 
soft if packed as described, but the result is anything 
but desirable. 

The writer had charge at one time of a hardening 
plant where, among other things, many hundred pairs 
of bicycle cranks were hardened every week. A lot 
of ten thousand crank forgings were received and 
started through the regular routine necessary to get 
them in a condition for hardening. When the first 
batch reached the hardener it was found impossible to 
harden them by ordinary processes. And, by the way, 



Results from wrong annealing. 

samples had been forged and sent us ahead of the main 
batch which had been tested and found all right. They 
hardened and tempered in a satisfactory manner and 
stood the required tests. 

The first test was made by placing each end of the 
crank on the two projections of an iron block, as shown 
in Fig. 29, and struck in the center a blow with a 
heavy hammer in the hands of an experienced inspec- 
tor. They were then taken to a testing machine and 
given a very severe test, which consisted in holding 
the end which went on the axle in a fixed position. 
Pressure was applied to the 
other end until the crank 
was bent a certain amount. 
The pressure 
was removed 
and the crank 
was supposed 
to come back 



!=£■ 




The Deny Collard Co. 



Figure 29. Testing a bicycle crank. 



straight, but 
the cranks in 
the large 
batch would 
not harden. 

Investigation at the forge shop where we procured 
them, showed that through some mistake the cranks, 
after being forged, were packed in cast iron dust or 
chips in the annealing pot. Orders had been given to 
anneal some machine steel forgings in this manner and 
to anneal the cranks in charcoal, but someone got the 
orders mixed, and hence the trouble. The cranks were 
made of 40-point carbon open hearth steel. We reme- 
died the defect by packing them in iron boxes with 



Si 



"Expended bone" for annealing. 

wood charcoal, and submitting" them to heat in the 
furnace for several hours after they were red-hot. In 
this way we got them in condition to harden. 

Another method which works nicely when applied 
to annealing machinery steel, but which is entirely un- 
fitted for tool steel, is to pack the pieces in annealing 
boxes in expended bone — i. e., bone that has been 
previously used in case hardening. As before stated, 
machinery steel packed in this manner, and heated, 
gives excellent results. It is also an excellent way of 
annealing cast iron (by this is meant small castings, as 
typewriter parts, etc. , which must be very soft in order 
to machine nicely). 

But tool steel should never be packed in any form 
of bone, as bone contains phosphorus, and this is the 
most injurious of any of the impurities which tool steel 
contains. The steel maker uses every effort possible 
to reduce the percentage of this impurity to the lowest 
possible point, for while it is a hardening- agent, its 
presence makes tool steel brittle, so that it is folly to 
pay a good price for steel on which the manufacturer 
has spent much time and money to rid of undesirable 
impurities and consequently must charge a high price 
for, and then use some method whereby the steel is 
charged with these very impurities. 

In concluding, it may not be amiss to emphasize a 
few facts that have already been mentioned. Do not 
overheat steel when annealing or it will be perma- 
nently injured. Do not subject it to heat for a longer 
period of time after it becomes uniformly heated 
throughout than is necessary to accomplish the desired 
result. For while it is necessary to heat the steel when 
annealing to as high a heat as will be needed in harden- 



Uniform annealing heat necessary. 

ing, and while the steel must be subjected for a period 
of time to heat that insures its being of the same tem- 
perature in the middle of the piece as it is at the sur- 
face, yet we must be careful not to overdo it. 

Steel kept at a red heat for a long period of time, 
even if it is not overheated, will betray the fact when 
the temper is drawn after hardening, if it does not at 
any other time. A piece of steel which is kept hot for 
too long a period when annealing, may apparently 
harden all right, but when the temper is drawn the 
hardness apparently runs out — i. e., when the piece is 
heated to a straw color it may be filed very readily, 
whereas a piece from the same bar not annealed, or 
which was pi'operly annealed and then hardened and 
drawn to the same temper color, would show all right 
— i. e., a file would just catch it. 

Uniform temperature when heating for annealing 
is as desirable as when heating for hardening. If a 
large block is unevenly heated, its corners and edges 
are hotter than the main part of the block. Violent 
strains are set up at these points, so it will be readily 
apparent that uniform heating during the various pro- 
cesses is one of the secrets of successful hardening of 
tool steel. 

There are other methods of annealing steel, 
methods whereby the surface does not become oxidized 
by the process of heating, as when heating drill rods, 
etc., but as these methods are not likely to be used by 
mechanics in every day shops, their consideration 
would be entirely out of place at this time. 

Lastly, remember that any process of annealing 
that takes from the steel any of its hardening proper- 
ties should never be used, no matter how soft it will 

8 4 



Baths for hardening. 

make the steel. It is better to work a piece of steel 
which is hard, than to unfit it for doing its maximum 
amount of duty when finished ; but it is possible to an- 
neal most steel so that it will be workable and yet 
harden in a satisfactory manner ; in fact, in a much more 
satisfactory manner than if not annealed. 

When annealing- high carbon steel, and it is desir- 
able to retain the full amount of carbon in the steel, it 
is advisable to pack in the annealing box with charred 
leather, instead of wood charcoal. 

When it is desirable to harden the surface of low 
carbon steel harder than it would naturally be, it may 
be machined nearly to size, packed in a box with charred 
leather and run for a length of time sufficient to give 
the desired results. After machining to shape, it may 
be hardened in the ordinary manner. 

Hardening Baths. 



?=^9 




CO 

When steel is heated to the proper hardening heat 
it is plunged into some cooling bath to harden. The 
rapidity with which the heat is absorbed by the bath 
determines the hardness of the steel. Knowing this, 
it is possible by the use of baths of various kinds to 
give steel the different degrees of hardness and tough- 
ness. A bath that will absorb the heat contained in a 
piece of steel the quickest, will make it the hardest, 
everything else being equal. A bath of mercury will 
cause a piece of steel plunged in it to be harder than if 
it were plunged in any of the liquids commonly used 

85 



Brine in "saturated solution." 

for this purpose, but as such a bath would be extremely 
expensive, it is but little used. Clear cold water is the 
one more commonly used than any other, and for most 
cutting and similar tools gives good satisfaction, 
although many old hardeners claim better success with 
water that has been boiled, or that has been used for 
some time, provided it is not dirty or greasy. 

A very excellent bath that is used very extensively 
is made by dissolving all the salt possible in a tank of 
water, or what is known as a " saturated solution." 
Salt water, or "brine," as it is commonly called, is 
used in most shops on certain classes of work, and in 
some shops it is used altogether where a bath of water 
is desired. 

Different kinds of oil are also used to accomplish 
various results. When small or thin cutting tools re- 
quiring a hard cutting edge are to be hardened, a bath 
of raw linseed oil, or neat's foot oil, is used. 

When toughness is the desired quality, as in harden- 
ing a spring, a bath of tallow, sperm oil or lard oil is 
used. But the nature of steel of different makes varies 
so much that no one bath answers best for all purposes, 
or for the same purpose, when applied to steels of dif- 
ferent makes. Sometimes it becomes necessary to use 
a bath containing two or three ingredients in order to 
accomplish the desired result. 

I have in mind a manufacturing concern who made 
a great many heavy springs. Until they changed the 
make of steel they had been using for years they had 
excellent results from hardening in lard oil, but after 
changing they could do nothing with this bath. After 
considerable experimenting they were advised to use 
the following mixture: Spermaceti oil 48 parts, neat's 

86 



Bath for hardening and toughening. 

foot oil 45 parts, rendered beef suet 4 parts, resin 3 
parts. They had very good results with this bath until 
a drummer came along with good cigars and a steel 
two cents a pound cheaper, and then trouble was the 
result. 

By the way, I have visited and known of several 
shops where a few good cigars or an occasional wine 
supper, which some glib-tongued salesman was willing 
to put up for the man who did the buying, caused more 
trouble than a little in the hardening department. But 
to return to the hardening of the springs. When the 
new steel came, the springs would not harden sufficiently 
in the mixture mentioned. They were finally advised 
to try a bath of boiling water, and this worked very 
nicely. 

Very small cutting tools, as taps, reamers, counter- 
bores, etc., harden nicely in a bath made by dissolving 
one pound of citric acid crystals in one gallon of water. 
This proportion may be used in making a bath of any 
size. 

The following is recommended when it is desired 
to have the tools hard and tough : 

Salt Yo, teacupful. 

Saltpetre y> ounce. 

Pulverized alum 1 teaspoonful. 

Soft water 1 gallon. 

The following bath gives excellent results, but care 
must be exercised in its use, as it is deadly poison. To 
six quarts of soft water put in one ounce of corrosive 
sublimate and two handfuls of common table salt. 
When dissolved it is ready for use. 

Sulphuric acid is added to water in various pro- 
portions, from one part acid to ten parts water, to 

87 



Rotting" steel by acid baths. 



equal parts of acid and water. Some even nse clear 
acid, and although excellent results, so far as the 
hardened surface is concerned, may be obtained by the 
use of this acid, steel makers do not advocate its use, 
claiming that the after-effects are injurious to the 
steel, that is, it "rots" the steel, and the writer's ex- 
perience substantiates the claims of the steel makers. 
I do not advocate the use of any of the acids, which act 
directly on steel, provided any other form of bath will 
give satisfactory results. 

There are many other compounds used with suc- 
cess in various shops. Some of these will be mentioned 

in connection with 
hardening various 
tools. As a rule, 
tool steel that is fit 
for use for cutting 
tools will harden in a 
satisfactory manner 
in clear w T ater. If the 
outline is irregular or 
it is desirable that 
it should be extra 
hard, a bath of brine 
answers admirably. 
Articles of an irregu- 
lar shape made of 
steel liable to crack 
when hardened should be dipped in water or brine (that 
is, warmed somewhat), the temperature of the bath de- 
pending upon the liability of the piece to crack. 

Tools, as milling cutters, made from high carbon 
steel, are many times hardened to advantage in a bath 

88 




The Dewy Coilard Co. 

Figure 30. Oil and water bath 
for hardening. 



Methods of cooling for hardening. 






^wmw' u 






=^S^,^ i^TfOjv; 



of water having- one or two inches of oil on the surface, 
as shown in Fig. 30. The article is brought to the 
proper temperature . in the fire and immersed in the 
bath, passing it down through the oil into the water. 
Enough oil adheres to the red hot steel, especially in 
the corners of 
the teeth or 
projections, to 
prevent the 
water acting as 
suddenly as it 
otherwise 
would, thus do- 
ing away in a 
great measure 
with the ten- 
dency to crack. 
It is a gx)od 
plan when hard- 
ening large 
pieces of almost 
any shape to 
first dip in water 

or brine and allow them to remain in this liquid until 
the surface is hard, then remove and instantly plunge 
into a tank of oil, allowing them to remain in the oil 
until cold. This works especially well in the case of 
such tools as milling machine cutters, punching press 
dies, etc., where it is not necessary that the hardened 
surface be very deep. 

The depth to which a piece is hardened depends 
on the length of time it is left in the water. For this 
purpose old hardeners allow the article to remain in the 



The Derry Collard Co 



Supply 



Ovecflow 



Figure 31. Hardening with jet 
from bottom. 



Various cooling methods. 

water until it ceases to "sing." This is the peculiar 
noise occasioned by putting a piece of reel hot steel in 
water. When the piece stops singing it is removed 
from the water and plunged in oil and left until cold. 

When pieces are to 
be hardened, and it is 
necessary to harden 
the walls of a hole or 
some depression, as 
the face of an impres- 
sion die, or forming 
die, or any similar 
piece, it is necessary if 
good results are de- 
sired, to have a bath 
which has a stream or 
jet coming up from the 
bottom, as shown in 
Fig. 31. If clear water 




The Derry ColIarJ Co, 



Figure 32. Continuous brine bath. 



is used in the bath, the inlet pipe may be connected 
with some constant supply, but if brine or some solu- 
tion is used, it becomes necessary to have a supply tank 
having a pump as shown in Fig. 32. The contents of 



QO 



Various cooling methods. 



the bath are pumped into the supply tank and run 

down the supply pipe as shown. 

At times it is desirable to have a tank in which 

there is no gush 
or jet of fluid, but 
where the con- 
tents of the bath 
are kept in mo- 
tion in order to 
force the steam 
away from the 
surface to be 
hardened. There 
are several ways 
of accomplishing" 
this. Fig. 33 
shows a bath hav- 
ing a pipe com- 
ing up from the 




The Uerry Collard Co. 



Figure 33. Bath with perforated 
bottom plate. 









bottom, the jet striking the plate which 
spreads the fluid. It then comes to the sur- 
face through the perforated plate shown. 

Fig. 34 shows a bath in which the 
contents are 
kept in motion 
by some me- 
chanical means 
contained in the 
tank. Such a 
bath may be 
made by follow- 
ing the sugges- 
tions Contained Figure 34. Bath with agitator. 

9 l 






- rV^-i-i' '-" -^ 




About heating baths. 

in the illustration. A tank of any convenient size 
may be made having a partition as shown. The por- 
tion of the tank marked a is intended to be used 
for the immersion of the articles being hardened, 
while b contains a pump, Archimedian screw or some 
similar device for forcing the water into the side a. 

If a pump is used, the water is forced through the 
pipe shown. If an Archimedian screw is used, the parti- 
tion shown should not extend way to the bottom, the 
water being forced under it. In either case it returns 
to b over the top of the partition c as shown, thus 
insuring a rapid circulation of fluid. This form of bath 
is especially to be desired where brine or some favorite 
hardening solution is used. It is also possible to heat 
the contents of the bath when it is considered advis- 
able, as in the case where articles are to be hardened 
that are liable to crack in contact with extremely cold 
liquids. Much more uniform results may be obtained, 
especially when small, thin pieces are hardened, if a 
uniform temperature can be maintained in the bath. 

In order to keep the contents of the bath at some- 
where near a uniform temperature, a small coil of 
steam pipe may be placed in the tank, and a ther- 
mometer may be so placed as to readily show the con- 
dition of the bath. While it may seem unnecessary to 
be so particular about the temperature (and it is un- 
necessary on most work, as an experienced hardener 
can determine the temperature very closely by the 
sense of feeling), yet there are jobs where it is essential 
that a certain uniform temperature be maintained in 
order to get uniform results. I do not mean by this 
that it is practical to attempt to keep the temperature 
within a few degrees of a given point, but it can be 

92 



Cooling dies with holes. 




Figure 35. Die with hole. 



kept somewhere near in order to get the best results 

possible. 

Sometimes it is necessary to harden the walls of a 

hole that does not go way through the piece, as a die 

used for compression work or 

some forms of dies for striking 

up cylindrical pieces. Fig. 35 

shows a sectional view of a die 

having a hole part way through 

it as described. Now, if a piece 

of work of this description were 

hardened in a bath where the 

contents were not agitated, it 

is doubtful if the Avails of the hole would be hardened 

in the least. The steam generated would blow the 
liquid out of the hole, and none 
could enter until the steel was cooled 
to a point where it could not harden. 
Better success would 
follow if it were dipped 
in a bath having a jet 
of water coming up from 
the bottom of the tank, 
but in this case it would 
be necessary to invert 
the piece in order to get 
the liquid to enter the 
hole, and if it were 

dipped in this position, it is probable that enough 

steam would rise to keep the contents of the bath from 

affecting the walls near the bottom. 

Now, in order to get satisfactory results when 

hardening work of this character, it will be found best 




Figure 36. Method of cooling 
holes in dies. 



9 3 



Cooling a shank mill. 

to have a bath so constructed that the liquid can run 
into the hole by means of a faucet or pipe, as shown in 
Fig. 36. If the hole is deep and 
there is danger of the steam pre- 
venting the liquid effectually work- 
ing at the bottom, a pipe may be run 
nearly to the bottom, as shown in the 
sectional view of Fig. 37. The pipe 
must not be as large as the hole, or 
the results will not be satisfactory. 





CTT5 O O O u CT~0 

Figure 37. Cooling a deep 

hole in a die. 

Sometimes it is necessary to 
harden several pieces of a kind 
whose outline betokens trouble 
if dipped in a cold bath, and 
yet it seems necessary to use a 
cold bath in order to get the 
desired result. Take, for in- 
stance, a shank mill of the 
shape shown in Fig. 38. If this 
mill is heated to the proper degree of heat and plunged 
in a dish containing just enough water or other liquid 
to harden the teeth before the water gets hot, the teeth 



Figure 38. Cooling a 
shank mill. 



94 



About using dirty water. 

will harden in a satisfactory manner, and the water will 
heat so as to do away with any danger of cracking the 
cutter from internal strains. The size of the dish will 
determine the depth of the hardening. When one 
piece is hardened the dish may be emptied and filled 
with cold water for the next. 

The writer has seen this scheme used with excel- 
lent results, not only on milling cutters, but on 
broaches, small dies, etc., that showed a tendency to 
crack when dipped in a large bath of cold fluid. Of 
course, it should be borne in mind that the dish 
selected for the bath must be large enough to hold a 
sufficient amount of liquid to harden the piece the 
necessary amount before it becomes too hot, but it is 
also essential that it should not be so large that the 
contents will not heat, because then there is no differ- 
ence in its action from that of a large bath. 

Generally speaking, however, it is advisable to use 
a large bath, having the contents at a temperature of 
about 60 degrees Fahr. , as then the process of con- 
traction, which takes place when the piece is cooling, 
is uniform. 

Delicate articles, however, require a bath having 
the contents heated somewhat above the temperature 
mentioned, the temperature depending on the character 
of the article and the nature of the steel. 

It should be borne in mind that a tank or dish of 
dirty water makes a very undesirable bath; neither 
should one be used having dirt in the bottom, because 
as the contents are agitated, the dirt rises, preventing 
the liquid acting in a satisfactory manner. 



95 



Baths for Hardening. 




The Lead Bath. 

When comparatively small pieces of work are to 
be hardened in large quantities, as, for instance, the 
various small parts of bicycles, sewing machines and 
guns, red-hot ' lead furnishes an excellent means of 
uniformly heating in a very economical manner. It 
is a speedy, and at the same time a very reliable 
means to use, as the heat can be maintained so uni- 
formly, it can be applied safely. By using a proper 
amount of precaution, there is no danger of burning 
the outside of the article before the center is heated. 
Large and small parts are heated alike, and quite a 
number of pieces can be heated at the same time, thus 
making it a cheap, rapid, yet reliable way of heating. 
It is necessary to have a uniform heat under and 
around the crucible that can be maintained for quite a 
length of time. 

A furnace burning illuminating gas as fuel, gives 
the most satisfactory results, although excellent results 
may be obtained by the use of a furnace burning gaso- 
line or crude oil. If it is not found possible to obtain 
any of these, good results can be obtained by the use 
of one burning charcoal, hard coal, or coke; but in 
order to obtain uniform results, a great deal of atten- 
tion must be paid to the fire. 

If but a few pieces are to be hardened at a time, 

96 



About lead and crucibles. 

and it is not considered advisable to purchase or make 
a furnace especially adapted to this kind of work, a 
crucible may be placed in a fire on an ordinary black- 
smith's forge. Build up around it with bricks, placed 
far enough away from the crucible to have a fire all 
around it, and fill this space with charcoal. It will be 
found necessary to raise the crucible occasionally and 
poke coals under it. 

The most satisfactory crucible is one made of 
graphite, especially for this purpose. A cast iron one 
is sometimes used, but as a rule is not as satisfactory 
and is more costly, as it burns out very quickly. 

The graphite crucible should be annealed before 
using, as this toughens it, reduces the liability of 
cracking and makes it longer lived. In order to anneal 
the black lead crucible, place it in any oven or furnace 
where a uniform heat can be obtained, heat it to a red, 
take it out and place it where it can cool off slowly 
without any drafts of air striking it. 

It is very essential that the proper quality of lead 
is used. Red-hot steel is very susceptible to the action 
of certain impurities. Many brands of lead contain 
sulphur in such quantities that it is very injurious to 
the steel. Nothing but chemically pure leads should 
be used. It is the custom in some shops to use lead of 
any kind, and when unsatisfactory results are obtained, 
the method, instead of the material, is condemned, be- 
cause the operator does not understand the cause of 
the trouble. 

If the lead contains sulphur, even in small quanti- 
ties, it will ruin the steel. The article will have a 
honeycomb appearance, and portions of the outside 
stock will be eaten away. When using lead that is 

97 



Mixture for hardening small tools. 

chemically pure, this difficulty will not be encountered. 

Many hardeners are averse to the use of the lead 
bath in hardening on account of the tendency of the 
lead to stick to the work. To prevent this trouble, 
different compounds are used. 

The writer has had excellent results with a solu- 
tion of cyanide of potash in water. Dissolve one 
pound of powdered cyanide and one gallon of boiling 
water. Let it cool before using. If this should not 
prove to prevent the lead sticking, put in a larger 
portion of cyanide. Some use a strong solution of salt 
and water. Dip the articles in the solution; place 
them where they can dry, preferably in a hot place 
where they will dry more rapidly. It is not safe to 
put them in the lead when damp, as any moisture 
would cause the lead to fly. 

The writer has used the following mixtures with 
very gratifying results when hardening such work as 
small milling cutters, taps, reamers, broaches, cherries, 
rotary files and similar tools having fine teeth likely to 
hold the lead. This formula is taken from the report 
of the Chief of Ordinance of the War Department, and 
is used in the U. S. Government shops when harden- 
ing files. The following is a copy of the report: 
"Before hardening, the files are treated with a mixture 
of salt and carbonaceous material to protect the teeth 
from decarbonization and oxidation. The kinds and 
proportions of the ingredients are exhibited in the fol- 
lowing table : 

Pulverized charred leather i ft). 

Fine family flour i)4 lbs. 

Fine table salt 2 lbs. 

The charcoal made from the charred leather should 

98 



The hardening of files. 

be titurated until fine enough to pass through a No. 45 
sieve. The three ingredients are thoroughly mixed and 
incorporated while in a dry state, and the water is then 
added slowly to prevent lumps, until the paste formed 
has the consistency of ordinary varnish. When ready, 
the paste is applied to the file with a brush, care being 
taken to have the teeth well filled with the mixture. 
The surplus paste is then taken off the file by the 
brush, and the file is placed on end before a slow fire 
to dry. If dried too quickly the paste will crack or 
blister. If not dry enough, the remaining moisture 
will be transformed into steam when dipped into the 
hot lead bath, and cause an ebullition or sputtering of 
the lead, throwing out minute globules of the latter, 
which may endanger the eyes of the operator. The 
fusing of the paste upon the surface of the file, indi- 
cates the proper heat at which the file should be 
hardened." 

File makers have methods of hardening files that 
differ very materially from the above process, but it 
has proved particularly valuable when applied to the 
tools mentioned. Small articles, if of an even size or 
thickness throughout, may be put into the lead when 
they are cold and left until red-hot, although they 
should be turned over occasionally. But pieces, such 
as shank mills and similar articles of irregular contour, 
having large and small parts in connection with each 
other, should be heated nearly to a red before putting 
into the lead, as the sudden expansion of the large 
thin parts would tear them from the more solid por- 
tions that could not heat and expand so quickly. 

The purpose of putting such pieces into the lead is 
for the uniform heat that can be finally obtained on the 

99 



Reasons for heating in lead. 

unequal sizes and thicknesses, making them much less 
liable to crack when dipped in the bath. If an irregu- 
lar shaped piece were plunged suddenly into the red- 
hot lead, and thereby cracked, it probably would not be 
noticed until it was hardened, and the natural inference 
would be that it had cracked in the cooling bath ; but a 
careful examination of the fracture would show the 
walls to be black, proving it to have been subject to 
heat after it was cracked. If it were sound until dipped 
in the bath, the walls would have a brighter appear- 
ance, although it might be somewhat stained by the 
contents of the bath, yet they would not be black. 

The following question may suggest itself. If the 
piece of work is to be partly heated in another fire, why 
not heat to the hardening heat? The reason for this is, 
that a much more uniform heat can be obtained in the 
lead crucible than in an ordinary open fire. When it is 
necessary to harden a portion of the piece, leaving the 
balance soft, it need only be dipped in the lead the re- 
quired distance, moving it up and down to prevent a 
fire-crack. It is likely to crack at the point where the 
heat leaves off, just as a piece of red-hot steel will 
crack if dipped into water in such a way that some of 
the red is out of the bath and the piece held in that 
position. It then cracks at the point where the con- 
traction ceases, while in the first case it cracks where 
the expansion ceases. 

If impossible to do the first heating in an open fire, 
or if it is considered advisable to heat it in red-hot lead 
altogether, the piece may be immersed in the lead, left 
there for a moment and withdrawn. It may then be 
immersed again, leaving a little longer than the first 
time and withdraw it again, repeating the operation 



How to handle lead for heating. 

until the steel is heated to a point where the intense 
heat will not cause it to crack from the sudden change 
of temperature. 

To prevent dross from forming on the lead, keep 
the surface covered with broken charcoal. This not 
only has a tendency to prevent dross forming, but the 
charcoal, catching fire and burning, keeps the surface 



K 



n 



id 



r ^ 



Figure 39. Mould for casting lead. 

of the lead at a more uniform heat, than if not used. 
But despite all these precautions, more or less dross 
will form in the surface of the lead. This should be 
skimmed off occasionally, in order that it may not stick 
to the work. 

When no longer using the crucible, the lead should 
be emptied out, as if left in the crucible until it cools 
and solidifies, the crucible will probably crack when the 
lead is heated again. It may be removed by means of 
a ladle and emptied into small moulds. When the cru- 



IOI 



Caution about too hot lead. 

cible is nearly empty, it may be lifted from the fire and 
the balance of the lead poured out. As it is necessary 
to put the lead into the crucible in small pieces, it is 
best to use a mold of the form shown in Fig. 39, as this 
makes a very convenient size to put into the crucible 
again. To get good results when hardening, the lead 
should be stirred up from the bottom occasionally in 
order to equalize the heat, as it will be hotter at the 
bottom than it will be toward the top. 

When heating pieces with fine projections or teeth, 
it is well to use a stiff bristle brush to remove any lead 
that may stick in the bottom between such projections. 
This should be done before dipping into the bath, to 
prevent soft spots. Steel will not harden where lead 
adheres to it, as the liquid in the bath cannot then 
come in contact with the steel. 

There is no one method of heating steel which is 
so generally used that is a source of more annoyance 
than the one under consideration, because attention is 
not paid to a few simple points. But if a chemically 
pure lead is used in the crucible, the contents of the 
crucible is stirred occasionally, and as low a heat as 
possible is maintained, excellent results will follow. 

A serious mistake, which is made many times, is 
to heat the lead too hot, leaving the piece of work in 
just long enough to bring the surface to the desired 
heat, then removing and quenching. The objection to 
this method is, the heat is not uniform throughout the 
piece, consequently poor results follow. If the article 
is left in the lead long enough to become uniformly 
heated throughout, it will become too hot. If the lead 
becomes too hot, it is best to plunge a large piece of 
iron or scrap steel into it, allowing it to absorb the 



Cyanide solution before heating. 




extra heat, thus reducing- it to the proper temperature. 
It is then safe to go ahead with the heating, and not 
until then. Do not neglect this precaution. 

It will readily be seen that the lead should be of 

about the same temperature as the steel should be 

heated, and the articles left in it 

long enough to become uniformly 

heated throughout. 

The hardener should 
bear in mind that the 
amount of heat given 
steel affects the struc- 
ture rather than the 
method of applying the 
heat. In order to use 
this method to advan- 
tage when hardening 
large quantities of small 
articles, quite 
a number of 
pieces may be 
heated at a 
time in the 
lead. This 
may readily 
be accom- 
plished by 

Drying steel before heating. dipping- a 




Figure 40. 



1 p p 1 n g 

number of pieces in the cyanide solution, laying them 
on the top of the furnace as shown in Fig. 40. When 
these are thoroughly dried, place them in the lead, dip 
another batch in the solution, and lay on the furnace 
as described. By this time the pieces in the lead will 

103 



How to handle work in lead furnace. 

be hot enough to dip in the bath. As one is taken from 
the lead, another may be taken from the top of the 
furnace and put in its place, another should be dipped 
in the solution and placed on the furnace. In this 
way a rotation may be kept up, which insures the 
maximum amount of work in a given time. 

Before taking a piece of work from the lead, it 
should be plunged below the surface and held there 
long enough to equalize the heat. Articles being 
heated in lead should be turned over occasionally, in 
order that they may heat uniformly. If long articles 
are to be heated by this means, it is necessary to stir 
the lead from the bottom frequently, or the piece will 
be the hottest at the end nearest the bottom of the 
crucible. 

When heating certain tools, as long reamers, 
broaches, etc., it is sometimes advisable to place a 
piece of cyanide of potassium on the surface of the 
lead. It will fuse and remain for some time in a body 
around the steel. The tool may be raised and lowered 
in the lead through this melted cyanide occasionally, 
and especially just before quenching in the bath. 

If the article is dipped in a bath of water, heated 
as hot as it is possible to hold the hand in, the teeth 
will be found very hard and the tendency to spring or 
crack will be reduced very materially. If it is desirable 
to have the tool extremely strong, that is, able to stand 
strains, as would be the case if a broach used for draw- 
broaching were being hardened, the tool could be 
heated as described and quenched in a bath of raw 
linseed oil, or into a bath of sperm oil and tallow, to 
which is added a small quantity of resin. The amount 
of resin added should be very small, as it has a ten- 

104 



Cyanide of potassium bath. 

dency to crystallize the steel if too great a proportion 
is used. Generally speaking-, one part resin to ioo 
parts of oil, or oil and tallow, will be sufficient, ancj 
generally it will not be found necessary to use it, if 
tallow is added to the oil. 

Although red-hot lead furnishes an excellent means 
of heating small articles, and a very satisfactory method 
of heating certain kinds of tools, yet for most cutti?ig tools, 
the writer has found cyanide of potassium, melted and 
heated red-hot in a crucible, or a mixture of salt and 
cyanide of potassium, to give more satisfactory results. 

Cyanide of Potassium Bath. 

Cyanide of potassium, if placed in a cast iron cruci- 
ble and heated red-hot, furnishes a method of heating 
steel that gives very excellent results in many shops. 
This method is employed very extensively in heat- 
ing articles whose 
shape betokens soft 
spots when hard- 
ened by the ordinary 
methods. It is also 
used in hardening 
dies for transferring 
impressions onto 
plates used in print- 
ing bank notes and 
similar work. 

The articles heat- 




Figure 41. Method of suspending work in 
cyanide of potassium. 



ed by this method are not subject to oxidation from 
the action of the air on the surface. The cyanide does 
not have a tendency to stick to the work, and the action 



105 



The action of cyanide. 



of the cyanide tends to increase the surface hardness, 
thereby making the tools more durable than when 
hardened by ordinary methods. 
Many dies with finely engraved 
working - surfaces are heated by 
this method and 
the best of re- 
sults obtained. 
In order to get 
satisfactory re- 
sults, it is neces- 
sary to use chem- 
ically pure cya- 
nide of potas- 
sium. 

It is different 
from red-hot 
lead in that iron 
will not float on 
its surface, but 
sinks to the bot- 
t om, conse- 
quently it is 
necessary to 
suspend the 
pieces being 
heated with 
wires which 
pass over the 
edge of the cru- 
cible in the form 
of a hook, as 




showninFig.41. 



Figure 42. Cyanide hardening furnace, 
also shown in Figure 18. 



106 



About attention to heat. 

As cyanide of potassium is a violent poison, the 
greatest care should be exercised when using it. The 
fumes of this chemical are very injurious to the work- 
man, consequently a furnace should be used having 
some means of conveying the fumes into a chimney or 
ventilating shaft. 

A furnace may be procured of the pattern shown 
in Fig. 42, using illuminating gas as fuel. A is the 
pipe furnishing fuel to the burners, B the crucible, C 
the hood, D the door, E the pipe which conducts the 
products of combustion to the pipe F, the pipe which 
conveys the fumes and products of combustion into 
the chimney. The lighting holes are stopped by the 
fire clay plugs G G. 

If it is considered advisable to make a furnace 
burning hard coal or coke, the same design may be 
used as illustrated in Fig. 19. For a lead hardening 
furnace, a hood must be added to prevent the poison- 
ous vapors getting into the room. This hood must be 
connected with the chimney. 

The operator must bear in mind that in order to 
get satisfactory results, attention must be paid to the 
amount of heat given the piece of steel, as previously 
explained. The strength of the hardened piece depends 
in a greater measure than mechanics generally realize, 
on the amount of heat given when hardening. In 
order to get the best results possible, it is necessary to 
have the steel at the refining heat. 

It is easy to be deceived when heating by the 
method under consideration, as the effect of the cyanide 
is to cause the surface of steel to harden at a tempera- 
ture lower than the refining heat. Consequently the 
portion beneath the surface may not be hardened at all 

107 



How to obtain colors. 



when the surface shows hard, if tested with a file. It 
matters not by what method steel is heated for harden- 
ing, there is a temperature at which it should be 
quenched. If not heated to that temperature, it is not 
as hard as it should be to accomplish the maximum 
amount of work possible. If heated to a higher tem- 
perature, the pores are opened, the steel made brittle 
and it is unfitted to do the amount of work it should. 

Not only is this method valuable because it fur- 
nishes a means of heating steel uniformly without 
danger of its sur- 
face becoming 
oxidized, but if 

certain points are T| Y^ .§ 

observed, the 
most beautiful 
colors imagin- 
able may be ob- 
tained. It is nec- 
essary, in order Tiie Derry Collard Co - 

to procure nice Figure 43. Heating in cyanide for colors. 

colors on the 

hardened product, that it be nicely polished, and free 
from dirt and grease. While grease will burn when 
subjected to a red heat, yet it leaves a stain on 
the work. 

When colors are wanted, articles made of tool steel 
may be suspended in the molten cyanide by means of 
wire hooks, which pass over the edge of crucible, as 
shown in Fig. 43. When the article becomes heated 
to a uniform heat, it may be removed and plunged in a 
tank of water, working it around well until cold, when 
it may be removed and dried. If it is desirable to draw 

108 




Hardening gun frames in colors. 

the temper and yet retain the colors, it may be done 
by heating in a kettle of oil, guaging the heat by a 
thermometer. The work must be left in the oil, away 
from the action of the air, until it is cooled below the 
point where temper colors are visible. 

This method of hardening is used very extensively 

in gun shops to 
harden gun 
frames, and at 
the same time 
procure the beau- 
tiful colors often 
seen on them. It 
works equally 
well on machin- 
ery steel or mal- 
leable iron. It 
is accomplished 
by attaching a 
piece of wire bent 
in the shape of 
a hook to the 
frame, the other 
end of the hook 
hangs over the 
upper edge of the 
crucible. It is 
necessary to have 
the article entire- 
ly under the surface of the cyanide. When it is 
heated for a sufficient length of time, which must be 
determined by experiment, it may be removed and 
plunged in a tank of water. In order to produce the 




The Derry Collard Co. 

Figure 44. Method for obtaining vine 
effect on tempered work. 



109 



Hardening malleable iron. 

beautiful vine-like effect often noticed, the inlet pipe 
may be situated about two feet above the tank, as 
shown in Fig. 44. The end of the pipe may be made 
to spray the water. The articles when taken from 
the cyanide crucible should be passed through the 
spray into the bath. Wherever the fine spray strikes, 
it produces the vine-like effect mentioned. The colors 
may be guaged by the heat given the contents of the 
crucible, also by the temperature of the bath. 

After using, a hook must be thoroughly dried be- 
fore putting in the molten cyanide, as the presence of 
moisture, even in the most minute quantities, will cause 
the cyanide to fly. If it strikes the flesh, it produces a 
burn, which, on account of the poisonous nature of the 
chemical, is liable to be very sore, but by avoiding the 
presence of any form of moisture, this need not occur. 

Articles made of malleable iron, as cutters for 
paper, and wood, may be hardened by heating in this 
manner. If only a few pieces are to be hardened, the 
cyanide may be heated in an iron dish of suitable size, 
the articles suspended in the dish until heated suffi- 
ciently, when they may be quenched in a bath of cold 
water, or warm water, according to the nature of the 
work to be done. Should this prove to make them 
too hard, a bath of tallow or oil may be used. 

Articles made of machinery steel may be heated in 
the cyanide crucible for hardening, the amount of 
hardness and depth which it penetrates depending on 
the amount of heat given and the length of time the 
article is left in the cyanide. 

If the articles are of a size that warrants it, they 
may be suspended in the cyanide by means of wires, 
as previously explained. If they are small and there 



To harden throughout. 

are many of them, they may be placed in baskets made 
of wire cloth and suspended in the molten mass. 
These baskets should not, however, be made of gal- 
vanized wire, or have any solder used in their con- 
struction, or the articles will be coated with lead. 
Care must be exercised when placing the articles in the 
basket, not to put in too many, especially if the basket 
is to be dipped into the hardening bath, as the pieces 
would touch each other when in the water ; consequently 
they would not be hard at these points. 

When it is desired to make articles other than cut- 
ting tools, and harden them throughout, it may be 
done by procuring a low grade steel, sufficiently high 
in carbon to produce the desired result. The steel 
may be either Bessemer or open hearth. If hearth 
steel, the temper must be suited to the particular pur- 
pose it is to be used for. When the article is ready for 
hardening, it may be suspended in the molten cyanide ; 
when it has heated for a sufficient length of time, it is 
removed and plunged in the bath. If hardness is the 
only quality desired, use a bath of water. If a hard 
surface is desired, and a very tough, strong interior, 
use a bath of oil and tallow. 

Malleable iron may be hardened by heating in 
cyanide of potassium, as is the case with machinery 
steel, the depth of hardening depending on the length 
of time it was left in the cyanide. If colors are desired, 
the surfaces must be polished, and a bath of clean 
water used. If a strong, tough effect is desired, 
quench in oil. 

It is sometimes desirable to color a piece of work 
in imitation of case hardening, yet leaving the article 
soft. If the piece is made of machinery steel of low 



Uniform heat necessary to hardening. 

carbon, or of malleable iron, this is accomplished by 
using a cyanide made especially for the purpose. This 
is known as "50 per cent, fused cyanide of potassium." 

Hardening Steel. 



^S9 




CO 

Having considered the nature of steel, methods of 
heating for different purposes, and the means of cooling 
by the various baths, we will proceed to the considera- 
tion of hardening articles of various types. As it would 
be impossible to consider all the articles that require 
hardening in the various shops throughout the country, 
such examples have been selected as are representative 
of the articles that are commonly hardened. 

Uniform heats are the secret of success when hard- 
ening steel. A greater part of the trouble experienced 
by men not skillful in this branch of the business arises 
from this fact not being observed. The writer cannot 
resist the desire to caution the reader against trouble 
arising from this cause, and hopes he will be pardoned 
if he apparently repeats this warning oftener than may 
seem necessary. 

When hardening steel, avoid too rapid cooling of 
the surface, as it is then rigid and inflexible, while the 
inside of the piece is still undergoing the change in 
structure incident to hardening. As a consequence, if 
the outer surface is hard and inflexible, and the internal 
portion is undergoing changes in size and structure, the 
outer surface will crack from the enormous strain 
brought to bear on it. It is advisable when hardening 



How to heat to avoid strains. 

small articles to heat the contents of the bath somewhat, 
to avoid the sudden cooling mentioned. 

As stated, when the surface becomes hard before 
the center has ceased changing- its size and. structure, 
there is a tendency to crack the surface from the in- 
ternal strains. 

To overcome this tendency, the piece should be 
heated to a degree that allows the surface to yield some- 
what and conform to the strains in the piece. The 
amount of heat necessary to produce this result has 
been ascertained 
to be at the tem- 
perature of boil- 
ing water (212 de- 
grees) . An ex- 
perienced hard- 
ener can deter, 
mine the necessary 
amount of heat 
very nicely by the 
sense of feeling, 
heat the steel until, 
when touched with 
the moistened 
finger, the peculiar 
snapping sound is 
heard. This is the 
same as the house- 
wife tells when her irons have reached the proper 
temperature for ironing linen. 

When pieces are hardened in large quantities, it 
becomes very costly practice reheating each piece over 
the fire, guaging the heat by the sense of feeling. A 




Figure 45. 



The Derry Col lard Co. 

Bath for hardening in hot water. 



113 



Cold baths not usually advisable. 

good plan in such cases is to have a tank of the descrip- 
tion shown in Fig. 24. A steam pipe is connected with 
the tank, as by this means it is possible to heat the 
water to any desired degree to the boiling point. A 
perforated pan is provided to catch the work as it is 
dropped into the tank. Occasionally the pan may be 
removed from the tank by means of the wires shown, 
the pieces emptied out and the pan returned. 

As the pieces are removed from the hardening bath, 
they may be dropped into this tank, and the tendency 
to crack overcome. For certain articles the brittleness 
is reduced sufficiently, making it unnecessary to draw 
the temper any more. 

The use of extremely cold baths is not as a rule 
advisable. Results fully as satisfactory so far as the 
hardened surface is concerned, are obtained if the bath 
is warmed somewhat, and the danger of cracking is 
greatly reduced. 

It is claimed that when articles made of steel and 
heated red-hot are plunged in a cooling bath, the out- 
side surface becoming chilled and consequently con- 
tracted, causes by this process of contraction an 
immense pressure on the internal portion of the steel 
which is red-hot ; this pressure has the effect of raising 
the temperature of the interior of the steel still higher, 
with the result that it expands still more. This extra 
expansion is, of course, communicated to the hardened 
(and consequently unyielding) surface, and this being 
unable to stand the immense strain, either cracks or 
bursts. 

If the contents of the bath are heated to some 
extent, the surface is not chilled below a temperature 
that allows it to yield somewhat, allowing it to con- 

114 



How to straighten hardened work. 




form in a measure to the internal pressure, which is 
relieved as that portion cools and contracts. 

The pliability of steel when warmed is illustrated 
in the case of such tools as taps, reamers, or drills, 
which become crooked when hardening. In order to 
straighten, it is necessary to apply a certain amount 
of heat. Place the tool between the centers of a 
lathe, with the convex side toward the operator, a 
piece of stock 
is then put in 
the tool post 
of the lathe, 
having one 
end against 
the bowed 
side, as shown in Fig. 46. 
The article is now heated 
until oil placed on the sur- 
face commences to smoke; 
pressure is applied by means 

of the cross feed screw and until the article is slightly 
bowing in the opposite direction. 

The piece should now be suddenly cooled while in 
this position. If it is not straight, the process should 
be repeated. Now, it is safe to spring the steel when 
warm, but when it is cooled, even after heating, as de- 
scribed, it will break if any great amount of pressure 
is applied. Should it spring somewhat when cold, it 
will return to its original shape when the pressure is 
removed, thus proving that hardened steel, when 
heated to a certain degree, is somewhat pliable. It is 
for this reason the surface of a hardened piece is 
reheated to " remove strains," as it is familiary termed, 

115 



Figure 46. 
Method of straight- 
ening work bent 
in hardening. 



Drawing the temper. 

or it is made pliable by heat, and in this condition con- 
forms to the immense strain incident to hardening. 

In the case of the article heated and straightened 
by pressure, it is necessary to cool the piece uniformly. 
Should one side be cooled and the opposite side left 
hot, the piece would probably crack from the unequal 
contraction. By carefully following this plan it will be 
possible to save many tools that would otherwise have 
to be thrown away — or which, if used, would not be 
satisfactory. 



Drawing the Temper 
after Hardening. 



CO 

When a piece of steel is hardened it becomes brit- 
tle. When the design of the piece is such that the 
working surface has sufficient backing, it is safe and 
advisable to keep the article as hard as when it comes 
from the bath. But in the case of tools having slender 
cutting edges, as taps, screw threading dies and mill- 
ing machine cutters of the ordinary styles, it becomes 
necessary to reduce the amount of brittleness in order 
that it may stand up when in use. This is done by re- 
heating the piece somewhat. 

The process of reheating also has the effect of soft- 
ening the steel to a considerable degree. It is not gen- 
erally desirable to soften it, but it is necessary to do so in 

116 



The amount of heat necessary to temper. 

order to reduce the brittleness. This reheating is gener- 
ally termed "drawing the temper." Unfortunately, 
the word temper is understood as having more than one 
meaning, and as a consequence people are sometimes 
puzzled to know exactly what one means when the term 
is used. By some it is understood as the double pro- 
cess of hardening and drawing the temper. To others 
it simply conveys the idea of drawing the temper of a 
hardened piece, and will be so used by the writer in 
connection with treating steel by heat, although the 
steel maker's definition of the word temper will be used 
occasionally to designate the percentage of carbon the 
steel contains. 

When steel is heated, the amount of heat it absorbs 
may be determined by the surface colors, provided it 
has been brightened previous to heating. It is custom- 
ary after hardening to brighten the surface with a stick 
whose surface has been coated with glue and then cov- 
ered with emery, or a piece of emery cloth may be 
attached to a stick or held on a file. After brightening, 
the piece may be subjected to heat. As the steel be- 
comes heated various colors will appear on the bright- 
ened surfaces. The first color visible is a faint straw 
color, then straw color, light brown, darker brown, 
brown with purple, light blue, darker blue. If heated 
to a black, the hardness is reduced to a point that 
makes the steel practically soft. 

The amount of heat necessary to give steel in 
tempering, depends on the make of the steel, how hot 
it was heated when hardening, and for what purpose it 
is to be used. The method ordinarily practiced has 
been briefly described above. 

When work is done in large quantities, the temper 
117 



Methods of drawing temper. 

is sometimes drawn by placing the articles in a pan 
having a long handle, as shown in Fig. 47. A quantity 
of clean sand is put in and the pan held over a fire, 
moving it back and forth, thus keeping the sand and 
work in motion. The surface colors can be closely 
watched and excellent results obtained. If there are 
any sharp edges or cutting teeth that will be harmed 
by striking against the other pieces, it is not advisable 
to use this method unless extreme care is exercised, 
but a pan of sand may be placed over the fire and a 
few pieces of work, having edges as described, placed 
in it and kept in motion by a stick, being careful not 
to hit them together. 

An excellent furnace, which is illustrated in Fig. 



Figure 47. Pan for drawing temper. 



48, can be procured, which gives very satisfactory 
results. The pieces to be tempered are placed in the 
pans, D D, which rotate at the speed of two or three 
revolutions per minute, the pans being hung loosely 
from rods connected with spokes around the driving 
block in the center, which receives motion from the 
worm and gear, A B, connected with power. The 
door, C, is closed and the furnace is charged with 
work, and may be opened for observation. When 
opened, the door forms a shelf or rest for the pans. 

118 



Revolving furnace for tempering. 



The thermometer indicates a degree of temper some- 
what different from the actual heat in the furnace, but 
if the temperature indi- 
cated is observed when 
the desired temper is ob- 
tained, the operation may 
be repeated 
with satisfac- 
tory results. 

This furnace 
is designed for 
tempering small 
articles, but the 
writer has used 
it with excel- 
lent results on 
punches used 
for punching 
rectangular 
holes 2 inches 
by s/s inch, the 
shanks being 
1% inches in 
diameter and 5 
inches long . 
The action of 
the furnace de- 
pends on the 

heated air, with Figure 48. Revolving furnace for 

temperature SO tempering small pieces. 

regulated that articles of irregular shape can be exposed 
to it long enough to impart the proper temper to the 
heavier parts without drawing the temper too low on 




"9 



Tempering lathe tools. 



the lighter parts of the same piece. By means fur- 
nished of regulating the heat generated, the injection 
of the heat evenly throughout the furnace is easily 
secured, and the overheating of any part of the piece 
prevented. 

A common method when drawing the temper of 
articles which are of a uniform thickness, is to heat a 
flat piece of iron to a red heat, lay the pieces on this, 
moving them around and turning 
them over occasionally to insure 
uniform heating. When the desired 
temper color shows, the piece is 
immediately immersed in oil to 
prevent its softening more 
than is desired. 

This method is , = ^ 

open to objec- 
tions when arti- 
cl es having 
heavy and light 
portions, which 
must be heated 




35S2S= 



.-.-.- . ^ 



Figure 49. 



The Derry-CoUard-Co, 

Hardening a diamond pointed 
lathe tool. 



alike, are to be 
tempered, be- 
cause the lighter 
parts, heating 
more quickly than the heavy ones, will become too soft 
before the heavier portions reach the desired temper. 

When tools having heavy parts adjoining the cut- 
ting portion are to be hardened, and it is not necessary 
to harden the heavy parts, as a diamond point lathe 
tool or similar article, it is the general practice to heat 
the tool for a distance on the shank — say as far back as 



Tempering in oil 



the dotted line in Fig. 49 — to a red heat. Plunge the 
cutting blade into the bath, being careful not to dip the 
portion marked a into the bath. Work up and down to 
prevent a water line, and move around to avoid steam. 
When the cutting part is sufficiently hardened, remove 
from the bath, and allow the heat from 
the heavy portion to run into the 
hardened part until the desired color 
shows, when it may be quenched to 
prevent its running any lower. 

When work is tem- 
pered in large batches, 
a very satisfactory 
method consists in put- 
ting the articles in oil 
and heating to a proper 
degree, gauging the 
heat by means of a 
thermometer. 

A very satisfactory 
tempering furnace is 
shown in Fig. 50. Illu- 
minating gas is used as 
fuel. The burning gas 
circulates around the 
kettle holding the oil, 
thus heating it very 
uniformly. The work is held in a perforated pail or 
basket, somewhat smaller than the inside of the kettle. 
The degree of heat to which the oil is brought is 
shown by the thermometer. 

If not situated so that a furnace of this kind is 
accessible, a kettle may be placed on a fire in a black- 




Figure 50. Oil tempering furnace. 



Oil tempering in a kettle. 

smith's forge and built up around with bricks, leaving 
a space up around the kettle for coals. Now fill the 
space with charcoal. As this catches fire, it heats the 
oil in the kettle. The articles to be tempered may be 
placed in the perforated sheet iron pail, at least two 
inches smaller than the inside of the kettle. The pail 
should have a flange at the bottom, as shown in Fig. 




o o o c o o 

o o o o o o o 

o o o o o o o 

ooooooooj 

ooocoooo 

OO'OOOOOOI 

|oooooooo| 
booooooo o;j 
I'-a-p-p-p-p-p-o^l 

Perforated Pail 



Figure 51. Oil tempering in a kettle. 



51, or it should be blocked up 1^ inches or 2 inches 
from the bottom of the kettle, to allow the oil to cir- 
culate freely beneath it. 

If the pail were to rest directly on the bottom, the 
pieces of work at the bottom of the pail would soften 
too much from coming in contact with the kettle, 
which is acted on by the direct heat of the fire. The 
thermometer should be placed between the pail and the 



122 



Temperature of temper colors. 

kettle, as shown. It is advisable to stir the oil in the 
kettle occasionally, in order to equalize the heat. 
When the thermometer shows the desired degree of 
heat, the pail containing the work may be removed, 
set to one side, where no current of air can strike it, 
and allowed to cool off. 

When pieces of hardened steel are placed in a 
kettle of oil and heated, the temper colors do not show, 
so it becomes necessary to gauge the heat by a thermo- 
meter. The temper colors are significant of a certain 
amount of heat which the steel has absorbed. 

Faint straw color 430 degrees Fahr. 

Straw color 460 " " 

Light brown 490 " " 

Darker brown 500 " 

Brown with purple spots. . 510 " " 

Light purple 530 " " 

Dark purple 550 " " 

Light blue 570 " " 

Darker blue 600 

Blue, tinged with green. . .630 " " 

Knowing the proper degree of heat to which a 
piece of steel should be subjected, it becomes possible 
to draw the temper on any number of pieces exactly 
alike, and much more uniformly than though they were 
gauged by color. As stated, 430 degrees of heat repre- 
sents a faint straw color, while 460 degrees a full straw, 
a difference of only 30 degrees, yet when tested with a 
file by one accustomed to this work, there is a vast 
difference in the hardness of the two. While the differ- 
ence in the two colors is slight, yet difference in the 
ability of the two pieces to resist wear in the case of 

123 



The necessity for proper temperatures. 

cutting" tools is quite noticeable. The average man 
does not detect a difference of 10 degrees by observing 
colors, consequently he is liable to have a product vary- 
ing in efficiency if he attempts to draw the temper by 
observing the color. But if he gauges the temper by a 
thermometer he can get his product within a limit of i 
degree or 2 degrees every day, and at a much less cost 
than if he were to draw to the color, provided the work 
is done in large quantities. 

At times a tool as it comes from the bath is too 
brittle to stand up well, yet when the temper is drawn 
to the first color discernible, i. e. , a light straw — it is 
too soft to do its maximum amount of work. Now, in 
a case of this kind the temper may be drawn to 200 to 
250 degrees, or any temperature that proves exactly 
right. 

The writer has in mind tools which, if left dead 
hard, would crumble away on certain projections when 
used; but if they were heated to the faintest straw 
color, would not do the amount of work required of 
them. But if they were taken from the hardening 
bath and placed in a kettle of boiling water (212 de- 
grees) and left there about five minutes, would show 
excellent results when used. Other tools showed best 
results when heated to 300 degrees and some to 350 
degrees. These facts are given the reader in order 
that he may understand that there is a method whereby 
the amount of brittleness in a piece of steel may be re- 
duced to a point where it will stand up to its work and 
yet not soften it as much as is necessary when it is 
drawn to the first temper color discernible. 

The colors visible on the brightened surface of a 
piece of heated steel are supposed to be due to a thin 

124 



Reasons for colors on brightened surface. 

coating- of oxide, formed by the action of the air on 
the heated surface. If a piece of steel is heated in oil 
away from the air, these colors will not present them- 
selves, provided the steel is left in the oil until the 
temperature is below the point necessary to show the 
faint straw color (430 degrees). 

It is necessary, in order to gauge the temper to 
which steel is drawn if gauged by temper colors, not 
only to have the piece bright, but it must be free from 
grease or oil, as the presence of oil will cause the 
colors to show differently than if the surface were 
clean. 

It is the custom in some shops to polish the 
hardened pieces and then draw the temper leaving the 
temper color as a finish. Now, if the work has been 
polished on a greased wheel, a certain amount of the 
oil is taken into the pores of the steel. When it is 
heated in tempering, this oil comes to the surface of 
the steel and produces a peculiar appearance. The 
surface appears streaked. If it is wiped with an oily 
piece of waste or cloth, this streaky or mottled look 
disappears. Many hardeners always wipe a piece of 
steel being tempered with some substance having oil 
or vaseline on it ; the appearance of the temper color 
is slightly changed by so doing, but allowance is made 
for this. 

When drawing the temper of articles which are 
small or thin, it is not advisable to heat by rapid 
methods, heating until the desired color appears and 
then quenching in cold water to keep it from running 
too low. The cold water, on account of the sudden 
chill which it gives an article heated to 430 to 500 or 
more degrees, has a tendency to make it more brittle 



Always harden at the lowest heat. 

than it would be if it were drawn to the proper temper 
color and allowed to cool off slowly, or plunged in 
warm oil or hot water. In the case of large, heavy 
pieces, or where brittleness would do no particular 
harm, this precaution need not be observed so closely. 
But on the other hand, if brittleness did no harm, it 
would not be necessary to draw the temper, because 
few tools are ever too hard for the purpose for which 
they are intended. For, as previously explained, the 
process of hardening makes them too brittle to stand 
up well when they are in use, consequently they are 
tempered to reduce the brittleness to a point where 
they will stand up. But the process of tempering is also 
(unfortunately for cutting tools) a process of softening. 

It should be the aim of the hardener at all times 
to harden steel at the lowest heat that will give the 
desired result, because in this condition the steel is the 
strongest possible, and consequently will not need the 
temper drawn as much as though it was given a higher 
heat and made brittle. Many times the writer has 
seen hardeners heat a diamond point turning tool to a 
temperature much hotter than was necessary when 
hardening, then draw it to a full straw color in order 
to reduce the brittleness so it would be able to cut and 
not flake off, or the surface cave in when the tool was 
cutting. 

Now, the tool in this condition could not do any- 
where near its maximum work in a given time. 
Neither would the life of the tool be as long as though 
it were hardened at the proper heat, and in this case it 
is doubtful if it would be necessary to draw the temper 
at all, provided it had not been improperly heated 
when forging. Many times tools of this description 

126 



Examples of hardening. 

can have the temper drawn sufficiently by immersing 
the tool after hardening in a dish of boiling water and 
leaving there a few minutes. 



Examples of Hardening. 



CO 

When hardening articles made of tool steel, it is 
necessary to consider, first, the nature of the steel used, 
the construction of the article, next the shape of the 
article, and the use to which it is to be put. It is also 
necessary to take into consideration the means of heat- 
ing furnished by the shop, and the bath to be used in 
quenching the article after it is heated. 

The operator should adapt himself so far as possi- 
ble to circumstances as he finds them, although it is not 
advisable to attempt the impossible, because a failure 
is generally counted against the man making it, rather 
than to any lack of apparatus necessary to do a job suc- 
cessfully. By this is meant that it is not policy to at- 
tempt to heat a piece of steel for hardening in a fire 
that cannot be made to heat the piece the entire length 
under a?iy conditions — that is, if it is necessary to 
harden it the entire length — because such an attempt 
must end in a manner disastrous to the steel. It is, 
however, the best plan to attempt to find some means 
whereby the piece may be heated properly by means 
of the apparatus at hand. 

The writer remembers, when a boy, seeing a tool 
127 



How a long reamer was heated. 

maker heating a long taper reamer. The only means 
of heating furnished by the shop was an ordinary black- 
smith's forge. By building a large, high fire he was 
not able to do a job satisfactory to himself, so he cleaned 
the fire out of the forge, and then took some fire brick, 




Figure 52. How a long reamer 
was heated. 



The Decry Collard Co. 



placing two rows on the forge, as shown in Fig. 52. 
On these he placed pieces of wire, about one-half inch 
apart, built two rows of bricks on top as shown, thus 
forming an oven, and then built a fire of charcoal on 
the wires between the bricks. By standing bricks up 
at the openings at the ends, he was enabled to get a 
very good fire in which he heated the reamer in a very 
satisfactory manner. 

While it would not have been wise to have pursued 
this method of heating, if there had been many pieces 
of the kind mentioned to be hardened, yet the fact that 
this man was able to adapt himself to circumstances 
and devise a way of doing a seemingly impossible 
thing, made him a valuable man in the estimation of 
his employers. It is the man who can do the seem- 

128 



The preference of some hardeners. 

ingly impossible things about a shop that is looked 
upon as the invaluable man, and it generally counts, 
as would be seen if his pay envelope was examined. 

While it is advisable, whenever possible, to study 
up some way of doing the work, do not attempt the 
impossible unless some one over you in authority 
assumes the responsibility. It is better to acknowledge 
your lack of ability than to spoil a costly piece of work, 
when it would have been considered advisable by those 
in authority to have sent the article to some one having 
the necessary equipment, had their attention been 
called to the matter. 

Cases like this may often be used to good advan- 
tage in pointing out the advisability of securing better 
facilities for hardening and tempering. As long as it 
is possible to get along without any equipment but a 
common blacksmith's fire, it is often very hard to 
obtain anything better. 



Hardening Dies. 



If it is necessary to heat a large die in an 
ordinary blacksmith's forge, it can be done. It is 
done right along by men who have had years of ex- 
perience, and very satisfactory results are obtained. 
The writer knows a man who is considered a very suc- 
cessful hardener. He does very little else but harden- 
ing large drop forging dies. He heats them in an open 
fire and has very good success. He could have, were 
he to ask for it, the very best equipment that money 
could buy, but he prefers heating by the method men- 
tioned. 

The writer also knows of an old man who lives 
129 



Poor scheme to heat in blacksmith's forge. 

four or five miles from the city. The electric cars run 
within five hundred feet of his house, but rather than 
ride on " them air new fangled devil's contraptions," 
as he calls them, he walks to the city, unless some of 
his neighbors give him a ride in their carriage. It 
may not seem to be a parallel case. If it isn't, the odds 
are in favor of the farmer, as there may be a certain 
danger in riding in the trolley cars. 

Now, it is possible to heat a large piece of steel, 
such as a drop forging die, in a blacksmith's forge by 
building a large, high fire of charcoal, placing the die 
on this, making certain that the face is buried in the 
live coals to a depth of several inches. It would be 
necessary to raise the die occasionally and work the 
coals under it, as it would not do to allow the air from 
the blast to strike the face. It is very necessary to 
heat the face uniformly. In order to do this it may be 
found necessary to move the die, so that some part 
that is heating slowly may be placed in a position 
where it will get more heat. 

Now, while it is possible to heat work of the descrip- 
tion mentioned by the method described, it is not policy 
to do it, provided any other means is at hand, or can be 
procured — that is, if there are many pieces to be hard- 
ened. If there are but one or two pieces, it is possible 
by using extreme care to get good results ; but if there 
are many of them it is folly, speaking from a commer- 
cial standpoint, to heat by this method. 

A furnace which gives very good results may be 
made, if it is not considered advisable to purchase one 
especially adapted to this class of work. Fig. 53 repre- 
sents a muffle furnace burning hard coal as fuel, 
although charcoal or coke may be burned ; but it will 

130 



; ' Home-made" furnace for die work. 

be found easier to maintain a uniform heat by the use 
of hard coal, and as the products of combustion do not 
come in contact with the piece being heated, they cannot 
in any way harm it. A represents the muffle which 
receives the work. This is located directly over the 



D 



1 












\ / 








Die 




1 




Bf 




IP! 




J 





r~T^ 




Figure 53. 



The Derry Cullard Co, 

; Home-made" furnace for die work. 



fire box B. The heat and gas from the fire pass up the 
sides and back of the muffle, thus insuring a very strong 
heat. The ash box C is provided with a door which has 
a sliding damper to furnish a draft for the fire. The 
smoke pipe is connected with the chimney. This is 
r ; lso provided with a damper to use in controlling the fire. 
The die may be blocked up from the bottom by 



13* 



Boxes for heating dies. 

means of several pieces of iron or fire brick to prevent 
the face coming in direct contact with the floor of the 
muffle. The door of the muffle should have an open- 
ing, which should be covered with a piece of mica in 
order that the heat may be readily observed without 
cooling the die. 

When many very large, heavy dies are heated it is 
advisable to have the bottom of the muffle on a level 
with the floor, 
sinking the fire 
box and ash box 
in the ground. 
By having the 
muffle on a level 
with the floor 
it is not neces- 
sary to raise the 
die in order to 
get it into the 
muffle. When 
it is not consid- 
ered advisable 

to do this, an iron platform may be built on a level 
with the bottom of the muffle. The heated die may 
be run out on this and then taken with tongs or grap- 
pling hook and carried to the bath. 

Other forms of furnaces which may be used for 
this purpose are illustrated under the section showing 
Methods of Heating. 

It is customary with some manufacturers who make 
a great many dies to harden them in the following man- 
ner : Take a box 2 or 3 inches longer and wider than 
the die, and 4 or 5 inches deeper. Put in about 2 inches 





_A / 




i 




1 


!>: 


o ^o 0o ov^ 0o ^^^l o ^^ o o ^ J o o ^^^o o ^^ 


:•: 


WMPM 




The Derry Collard Co. 

Figure 54. Box for heating dies in 
charred leather. 



132 



Proper methods for heating dies. 

of granulated charred leather, place the face of the die 
on this, as shown in Fig. 54, then fill the box with 
leather. 

Some hardeners use a box large enough to take in 
the whole die and allow for a cover on top. It is then 
entirely removed from the action of the fire, even if 
heated in a furnace where the work is placed directly 
in the fire. But as it is not possible to get a test wire 
down through the center of the die, and a wire at the 
sides of the die would not show the amount of heat the 
die contained, and as there would be no means of 
observing the heat, the operator would have no means 
of knowing whether the die was too hot or not hot 
enough, or whether it was heating uniformly. And as 
the decarbonization of the surface of the upper part of 
the die is of little consequence, the plan suggested by 
Fig. 54 will be found the most satisfactory, as the 
heats can be watched and the die moved occasionally 
in order to equalize the heat, which is apt to be greater 
in one part of the furnace than in another. The furnace 
should not be heated much above the temperature 
desired for the die. It is better to take a longer time 
in heating than to heat unevenly, thereby setting up 
strains which are bound to manifest themselves when 
a piece is hardened, or if they do not at that time they 
will shortly afterward. 

When the proper heat has been obtained, the box 
may be removed from the furnace and the die taken 
out and plunged into the bath. The form of bath 
used for this class of work differs, some hardeners pre- 
ferring one with a jet of water coming up from the 
bottom, as shown in Fig. 55. This works very nicely 
if the impressions are not too deep, in which case the 

133 



Bath for hardening dies. 

steam formed has a tendency to rise in the impressions 
and keeps the water from going to the bottom. When 
dies of this description are to be hardened, a bath may 
be constructed with an overhead pipe, as shown in Fig. 
56. By this means the die is placed on the rods shown, 
and when the water is turned on it will go to the bot- 
tom of any im- 
pression that 
would be likely 
to be in any die. 
This form has 
the further ad- 
vantage that a 
cupful of strong 
solution of salt 
and water, pot- 
ash and water, 
or cyanide of 
potash and 
water may be 
dashed on the 
face and into 
the impression 
just ahead of the 
jet of water. This has the effect of starting any scale 
that may have been formed after the die was exposed 
to the air. 

Some hardeners have rods in the bath for the face 
of the die to rest upon, as shown in Fig. 55, then allow 
the jet to play against the face, while others claim bet- 
ter results if the die is worked up and down somewhat 
in the bath as described. 

It is customary with many manufacturers who 




Supply 



Overilow 



Figure 55. Bath for hardening dies. 



J34 



On 



Figure 56. 
Bath for hard- 
ening dies. 



Baths for hardening dies. 

have many dies of this character to harden, to use a 
bath having an inlet pipe coming - up from the bottom, 
as just shown. When the die is properly heated, 
it is placed on the rods with the dovetailed tongue 
down ; the stream of water is allowed to play against 
this side of the die until it is 
somewhat cooled ; this not only 
prevents this portion springing 
when the face is hardened, but 
it allows the heat to run to the 
face of the die. 

After the 
tongue side is 
sufficient^ 
cooled, the die 
is turned over 
and the stream 
of water is di- 
rected against 
the face ; the 
overflow is 
checked suffi- 
ciently to allow 
the water to 
rise several 

inches above the face, on the sides of the die ; that is, 
it is immersed several inches in the bath; the depth 
of immersion depending on the character of the die and 
the custom in the individual shop. 

When dipping large, heavy dies in the bath, it is 
advisable to hold the die with a pair of grappling 
hooks, as shown in Fig. 57. These should be attached 
to a rope or chain and operated by a pulley, in order 




Overflo 



135 



Tongs for handling heavy dies. 



that the die may be raised and lowered somewhat in 
the bath. Then again, it would not be advisable for 
the workman to dip so large a piece of steel with tongs 
that necessitated holding his hands and arms over the 



bath, as the im- 
mense volume of 
steam would be 
liable to burn 
him ; neither 
could he properly 
support the die 
in the bath. 




Figure 57. 

Tongs for 

handlin 

heavy dies. 



Excellent results 
may be had by the 
use of a furnace built 
expressly for this 
class of work (see 
Fig. 58). The die A 
is supported on a 
platform B, and is 
raised mechan- 
ically, so that 
the amount 
which it is nec- 
essary to hard- 



en is in the furnace, while the rest of the die is below 
and removed from the action of the heat. The heat- 
ing chamber is on top, with burners entering opposite 
sides and projecting the name against the top lining 
and distributing it evenly. The die should not be 
placed on the platform until the furnace is evenly 
heated, when it may be raised by means of the lever 
D, until the face enters the furnace the desired amount. 
The face of the die can be observed through the open- 

136 



Heating dies with a gas furnace. 



ing C. When heated to the desired degree, the plat- 
form is lowered, the die withdrawn and quenched. 
The weight of the die is counterbalanced 
by the weight shown, which can be shifted 
as occasion requires. 

Dies used in 
making molds 
for hard rub- 
ber and similar 
work, whose 
faces are en- 
graved, may 
be packed as 
described and 
represented in 
Fig. 54, and 
run until the 
required heat 
is attained. 
After the heat 
becomesequal- 
ized — i. <?., the 
same through- 
out — t he die 
may be dipped 
in the bath of 
brine, using 
the arrange- 
ment shown in 

Fig. 57. It is necessary to get the die in the bath as 
soon as possible after removing from the packing- 
material in order to prevent oxidation of the face 
containing the engraved work. 




The Deny Collard Co. 



Figure 58. Gas furnace for heating dies. 



3 7 



Punching press dies. 

Dies for punch press work, especially those used 
for blanking — that is, punching blanks from sheet or 
other stock — occasion a vast amount of trouble in many 
shops when they are hardened. Observation has led 
the writer to believe that most of the trouble is caused 
by uneven heats. The corners and edges of the block 
and the edges surrounding the openings will heat much 
more rapidly than the balance of the die block unless 
extreme care is used. 

Before putting the die in the fire, all screw and 
dowel pin holes and holes for guide pins (stops) should 
be filled with fire-clay, mixed with water to the consis- 
tency of dough. This prevents the contents of the bath 
entering the holes, and reduces the tendency to crack. 
The die should, if possible, be heated in a muffle fur- 
nace, not heating the furnace much, if any, hotter than 
the desired heat for the die. When it is to the proper 
heat and uniform throughout, remove from the fur- 
nace, catch by one end with a pair of tongs and lower 
into a bath of brine. Swing slowly back and forth in 
the bath, in order that the contents of the bath may 
pass through the openings. This insures the harden- 
ing of the walls, as otherwise the steam generated 
would force the contents of the bath away from the die 
until it had cooled to a point where it would not harden. 
When the die ceases to sing, it may be removed and 
plunged into a tank of oil. 

There is not much danger of a die cracking when 
dipped in a bath, provided it was annealed after the 
blank had been machined all over and the openings 
blocked out somewhere near to shape. But it is ex- 
tremely essential that the utmost care be taken when 
heating for hardening. Be sure that no part of the die 



How to prevent cracking of dies. 

block is heated any hotter than it should be. The heat 
must be uniform throughout the piece. If the shape is 
one that betokens trouble, it is advisable to heat the 
contents of the bath considerably. Generally speak- 
ing., it is not advisable to use an extremely cold bath 
on this class of work. 

The writer prefers using- a tank of generous pro- 
portions, so the contents would not be materially 
affected by the heated piece, and heating the liquid to 
a degree that does away with any tendency to crack 
the piece. An excellent method to prevent the ten- 
dency to crack from internal strains, consists in placing 
the die, after hardening, in a kettle of boiling water, 
keeping the die in the water at this temperature for 
one or more hours, according to the size of the die. 

If the temper is to be drawn immediately after the 
die is taken from the bath, a flat piece of cast iron or 
scrap steel may be heated while the die is being heated, 
and quenched. It is customary with some hardeners 
to heat the piece red-hot. Brighten the face of the 
die and lay it on the heated iron. The die should be 
moved around on the heated piece and turned over 
occasionally to heat both sides alike. When the temper 
has been drawn the desired amount, the die may be 
immersed in oil, thus preventing the temper being 
drawn too much. 

While it is the custom of many hardeners to heat 
the drawing plate red-hot, as explained, before placing 
the die on it, the writer considers it better practice to 
heat the plate somewhat, leaving it over an open fire. 
Place the die on the plate and gradually raise the heat. 
It is rather rough treatment for a piece of unyielding 
hardened steel to be brought in direct contact with 

i39 



Don't bring steel to sudden heat. 

extreme heat, and is liable to crack the surface of the 
steel in innumerable places, especially if the operatoi 
is not thoroughly experienced in this line of work. 

The amount necessary to draw the temper of a 
blanking die depends on the steel used in its construc- 
tion, the temperature it was heated to when hardened, 
and the nature of the work to be performed by it. 

Generally speaking, it is advisable to refer the 
matter of how hard the die or punch should be to some 
one familiar with the requirements of the work to be 
done. In some cases it is desirable to have the punch 
the harder of the two, although, generally speaking, the 
die is left harder than the punch. In some shops, the 
one that requires the greater expense in making is left 
the hardest, in order that it may be the least injured in 
case they strike together when in use. In such cases 
it is necessary to draw the one that is desired softest 
considerable lower than the other. 

But as the circumstances must govern the relative 
hardness of the two, no hard and fast rule can be given. 

It is customary to draw to a temperature varying 
from that which produces a faint straw color, to a 
brown with purple spots. 

Probably no one class of tools used in machine 
shop work requires greater care on the part of the 
hardener than the hardening and tempering of punches 
and dies ; and probably no class of tools involves a wider 
range of methods of hardening and degrees of hardness 
essential to produce desired results in the individual 
shop. 

The hardener who is desirous of giving satisfac- 
tion will study the conditions in the shop where the 
tools are to be used. He will also consider the steel 

140 



Hardening the punch. 



used in the construction of the tools and the nature of 
the stock to be machined. It will be necessary also to 
get the experience of men familiar with the work to be 
done, because a die and punch hardened and tempered 
in a manner that insured satisfaction in one shop would 
not meet the requirements in some other shop. 

When hardening the punch, use extreme care in 
heating. If the punch is strong and is to be used for 
punching comparatively light stock, it is not necessary 
to harden it the entire length. Take, for instance, the 
punch shown in 
Fig. 59, to be 
used for punch- 
ing sheet steel 
-iV inch thick. 
This will work 
satisfactorily if 
hardened to 
the dotted line 
shown. 

When, how- 
ever, it is neces- 
sary to harden a 
piercing punch of 
the design shown 
in Fig. 60, it will 
be found neces- 
sary to harden 
the entire length 
of the end #, if 
the punch is to be 
used on heavy 

Stock. Should Figure 59. Punch for ^g inch steel plates. 



141 



Kind of steel to use for punches. 

the hardness extend only to the dotted cross line, it 
would buckle, as shown in Fig. 61, when punching 
stock as thick as the diameter of the punch. 

When making punches that are heavy and strong, 
and which must retain a good edge, it is advisable to 
use a steel of comparatively high carbon. But if 



Figure 60. Piercing punch for heavy work. 

punches are made of the form shown in Fig. 60, best 
results will follow if a comparatively low carbon steel 
is used, as it is not as liable to crystallize as if a higher 



Tha Derry Collard Co. 

Figure 6 1 . Result of hardening only as far as the dotted line, 
as shown in Figure. 60. 

steel were used. As a rule, drill rod does not give 
good results when used in making tools of this de- 
scription. 

When punches are sufficiently strong, it is advis- 
able to apply the heat at the shank end when draw- 
ing the temper. A block, as shown in Fig. 62, having 
several holes a trifle larger than the shanks of the 
punches may be heated red hot and the punches placed 
in these holes. When the desired temper color is visi- 

142 



How to heat slender punches. 

ble at the cutting end, the punch may be taken from 
the block and dropped in oil to prevent its becoming 
too soft. The upper end of punch will, of course, be 
softer than the cutting end. 

When a long, slender punch, of the design shown 
in Fig. 60, is to be tempered, and the punch is to be 








I 




■ 




ll 


IR 







The Derry Collard Co. 

Figure 62. Heating block for tempering long, slender punches. 

subjected to great pressure, it must be hardened the 
entire length, and the temper drawn equally the whole 
length. This can be accomplished by heating in a 
heating machine of the design shown in Fig. 48, or the 
punches may be placed in a pan containing sand and 
drawn over a fire. Or they may be placed in a kettle 
of hot oil, gauging the heat by means of a thermometer. 

If intended for piercing a heavy, tough stock, they 
will be found to work very satisfactorily if drawn to 
a full straw color, 460 . 

Many hardeners and others look askance at ther- 
mometers and always associate them with theory 
rather than practice, with the laboratory rather than 



143 



Forming and ring dies. 

the workshop. In reality they are just as practical a 
tool as a steel scale or a micrometer, and, like them, 
enable us to measure rather than to guess. 

Forming Dies. 

When hardening forming dies or dies for compres- 
sion work, if a great amount of pressure is to be exert- 
ed in order to perform the necessary work, the dies will 
not stand up as well if hardened at a low heat as though 
heated somewhat hotter. The outside surface will be 
hard, but under pressure this surface will be forced or 
crushed in, the interior not being hard enough to resist 
the pressure on the outer surface. It is, as stated, 
sometimes necessary in such cases, to heat the block 
somewhat hotter than if it were a cutting tool, yet care 
must be exercised that the piece be not overheated. 
But while it may be advisable to heat somewhat hotter 
than is the case with most tools, the heat must be uni- 
form throughout the die. 

It is not, generally speaking, advisable to draw the 
temper very much on tools of this description, but it is 
necessary to remove the tendency to crack from in- 
ternal strains. This is done by heating the die over a 
fire until it is at a temperature that makes it impossible 
to hold the hand on it, yet not hot enough to percep- 
tibly start the temper, or it may be boiled in a kettle 
of water for several hours. 



Ring Dies, 



When hardening large ring, dies or pieces of a cir- 
cular shape, whose size and weight make it impracti- 



144 



Furnace for ring dies. 

cable to harden by ordinary methods, it is a good plan 
to heat in a furnace made especially for this class of 
work. Such a furnace is seen in Fig. 
63, which shows a circular block A in 
position for heating. It is resting on 
strips of iron C supported by pieces 
of fire-clay B. The circular piece be- 
ing heated should be in the center 
of the furnace—/, e., evenly dis- 
tant from the inner 
walls. The cover D 
is attached to 
the mecha- 
nism for rais- 
ing the cover, 
and held by 
the chains EE. 
It is possible, 
by using prop- 
er care, to heat 
work very uni- 
formly in a 
furnace of this 
description. 

A method 
the writer has 
used with ex- 
cellent results 
when harden- 
ing work of this character, consists in placing the 
ring or circular die in an iron box two or three inciies 
larger each way inside than the circular piece. A cir- 
cular box gives better results than a square one, as 




The Derry Collard 



Figure 63. Gas furnace for ring dies 
and similar work. 



45 



Box for heating ring dies. 



Figure 64. 

Method of removing ring 

dies when heated 

in boxes. 



more uniform heats may be obtained. Place i : _> 
inches of a mixture of equal parts granulated charred 
leather and charcoal in the bottom of the box. Place 
the piece of work on this, cover with the mixture 
to a depth of an inch or so, put the cover on the box 
and place in the furnace. 

When the piece is of a uniform red heat, the box 
may be removed from the furnace and the piece of 

work taken out by 
grasping it with 
tongs on opposite 
sides, as shown in 
Fig. 64. Place it 
on a device which 
consists of a ring 
having three han- 
dles, as represented 
in Fig. 65. Have 
the ring (which 
should be made of 
iron or machinery 
steel) considerably 
thinner than the 
thickness of the piece to be hardened, but wide enough 
to screw the handles in as shown. The handles b b 
are threaded on one end and bent ; they are then 
screwed into the ring, as shown. A stud c having a 
tapped hole is screwed in also. The third handle is 
screwed into this. The object of making it by this 
method is, the handle may be unscrewed from the stud 
c and the piece to be hardened put in place. The 
handle may then be screwed into the hole in stud. If 
the piece of work is very large and heavy, a man may 

146 



Device for handling large ring dies. 

be stationed at each handle. If not very heavy, two 
men can handle it all right. The operators should 
protect their hands and arms in some manner to pre- 
vent being- burned by the steam generated when the 
red hot piece comes in contact with the water. 

It will be necessary to use a bath having a jet of 
water coming up from the bottom, so as to cool quick- 
ly, when harden- 
^ ing work of this 

description. Be- 
fore immersing, 
the water should 
be turned on, and 
at the minute the 
piece is dipped, a 
quantity of table 
salt (about a pint) 
should be thrown 
into the water. 
The ring should be 
worked up and 
down in the bath. 




The Deny Collar J Co. 



When the 



sing- 



ing" ceases, the 
supply valve may be closed. The water in the bath 
may become somewhat warm, but it will reduce the lia- 
bility of cracking. As soon as the piece of work is 
reduced to the temperature of the bath, it may be re- 
moved, placed over a fire and heated to prevent crack- 
ing from internal strains. If it is necessary to draw 
the temper, the piece of steel may be brightened while 
heating and the temper drawn at this time. 

It is advisable when drawing the temper of articles 



H7 



Forms of screw cutting dies. 

of this description to heat very slowly, so as to have all 
parts of an equal temperature. If possible, have the 
heat so uniform that it will not be necessary to quench 
the article when the desired heat is reached. Should 
the temper colors, however, run so fast that it seems 
necessary to quench in order to keep it from becoming 
too soft, it should be dipped in oil or hot water, as, if 
dipped in cold water, it would have a tendency to cause 
brittleness. 

Screw Threading Dies. 

There are several forms of the die under considera- 
tion. They are sometimes made square, then again 
they are made round in shape, with no means of ad- 
justment. They are then termed solid dies. Most 
square dies are made solid. 




The Derry Collard Co. 

Figure 66. Various styles of screw 
threading dies. 

When it is necessary to cut a screw to size or to 
gauge, it is generally considered advisable to make the 
finish die of a form known as an adjustable die. The 
forms referred to are shown above, in Fig. 66. 

The solid square die, being used mostly for thread- 
ing bolts and similar work where accuracy is not 
essential, are usually made to cut small enough, and no 
particular pains taken when they are hardened. How- 

148 



Holder for hardening screw dies. 



ever, if a die of this form is hardened all over, the con- 
traction from the outside edges is very unequal, on ac- 
count of the corner containing more stock than the 
portion between. Owing to the unequal contraction, 
the cutting edges do not have an equal amount of 
work to do, so one cutting edge dulls more rapidly 
than the other. Every tool maker knows the secret of 
success in making a screw threading die that will work 
satisfactory, lays in having each cutting edge cut its 
proportional amount. It will readily be seen that any 
unequal contraction or wear, which causes an upsetting 
of this equality in cutting, must reduce the usefulness 
of the tool. 

Too often no account is taken of the amount of work 
a tool will do after it is hardened. If it survives the 
ordeal of going through the fire and water, and will 
cut, it is considered a successful job of hardening. 

From the preceding it will be seen that it is neces- 
sary, in order that best re- 
sults may follow, that the 
die be in (as near as possi- 
ble) the same shape, and 
the location of the cutting 
edges be the same as be- 
fore hardening. Now, in 
order to accomplish this 
result, it is necessary to 
treat the die in a manner 
that will cause the cutting 
portion to harden first. By 
so doing, the contraction 

Figure 67. Device for cooling screw of the ° llter portion does 

threading dies. not seriously affect the cut- 




149 



How to prevent "twist" in screw dies. 

ting qualities of the tool. When hardening a square 
or a solid round die, it is sometimes considered advis- 
able to place the die in a fixture, as shown in Fig. 
67. It is then immersed in the bath and swung slowly 

back and forth in 
order that the liquid 
may readily pass 
through the opening, 
thus insuring the 
hardening of the cut- 
ting teeth. The por- 
tion near the circum- 
ference is, of course, 
soft. This is rather 
to be desired than 
otherwise in the form 
of die under consid- 
eration. 

When adjustable 
dies are hardened, it 
is generally consid- 




Figure 68. Method of preventing "twist" 
in screw threading dies. 



ered necessary to harden the outer portion in order 
to furnish a certain amount of elasticity, in order 
that the die may open 
uniformly when ex- 
panded. The necessity 
of this depends on the 
design of the die. If 
stock enough is left at 
the portion where the die is supposed to spring, the 
stiffness of the stock will give it sufficient tension. 
Should it be necessary to harden the outer portion 
somewhat, the fixture may be cut away in a manner 



Figure 69. Example of "twist' 
in screw die. 



150 



Cooling dies for screw cutting. 

that allows the contents of the bath to come in contact 
with the steel nearer the outer edge. 

Adjustable dies of the description shown should not 
be cut entirely through at the point where pressure is 
applied to open them, but may be cut nearly through, 




Figure 70. Method of cooling dies for thread cutting. 

commencing at the inside and cutting toward the out- 
side, leaving a thin partition, as shown in Fig. 68. 
This partition holds the die in shape, preventing the 
tendency to twist, shown in Fig. 69. 

When it is not considered advisable to make or use 
a fixture as described, the die may be grasped, after 
being heated, with a pair of tongs, as shown in Fig. 
70, and quenched in a bath of lukewarm water or 
brine, swinging it slowly back and forth, as repre- 
sented. When hardening any tool of this description, 



Drawing the temper of a "spring" die. 

bear in mind the fact that the article should never be 
heated in a manner that allows the cutting teeth to 
become oxidized by exposure to the air while heating. 
Best results are obtained by heating in a muffle or a 
piece of pipe. If the surface of the teeth become 
covered with a scale of oxide, this raises, and keeps the 
contents of the bath from acting, thus causing soft 
spots, which render the tool practically useless. 

An excellent plan consists in heating the dies in an 
iron box having a half inch of charred leather in the 
bottom. Fill the opening in the die with the same 
material. When the die reaches a uniform tempera- 
ture which is right to produce the desired result, 
quench in the bath. 

When hardening "spring" dies, or, as they are 
familiarly termed in some shops, "hollow mill dies," 
best results are obtained by dipping in the bath with 
the cutting end up- 
permost, as de- 



scribed under Hard- 
ening Hollow Mills. 



Figure 71. 
Drawing the temper of 
a "spring" 




Generally speaking, it is not necessary to heat the die 
much beyond the length of the threads. 



is- 



Tempering small dies. 

The temper may be drawn by placing the die on a 
hot plate, as shown in Fig. 71, drawing from the back 
end. On account of the shape of the cutting edge, 
which makes it stronger than the ordinary form of 
screw threading die, it is not necessary to draw the 
temper as much. A faint straw color making them 
about right, unless the cutting tooth is long and weak, 
in which case it may be drawn to a full straw color. 

If many dies are to be tempered at a time, the cost 
may be reduced very materially by heating in a kettle 
of oil, drawing them to a temperature which varies 
from 460 to 500 , according to the conditions pre- 
viously mentioned. 

When but one or two are to be done, it is advisable 
to brighten the sides and draw the temper by laying 
them on a flat plate, moving around on the plate, and 
turning them over occasionally. The temper color 
should be from a straw to a brown color. If it is con- 
sidered advisable to draw the temper of a large batch 
of dies by the hot plate method, the plate may be 
placed over a fire, in order to maintain a uniform heat. 
Quite a number of dies may be placed on the plate at 
a time. It is necessary to turn them occasionally, as 
mentioned. As one shows the proper temper color, it 
may be removed and placed in a dish of warm oil. By 
this method a skillful operator can temper a large batch 
of dies in a comparatively short space of time, but the 
results will not be as satisfactory as though heated in oil. 

The amount of work to be done will always deter- 
mine the most economical method of doing it, but it is 
better to err on the side of having too many convenan- 
ces. A few spoiled tools will pay for several improve- 
ments. 

153 



Cracking of dies from internal strains. 

Large pieces of steel are more liable to crack as a 
result of internal strains than smaller pieces. On ac- 
count of the weight of the piece there is a tendency on 
the part of some hardeners to neglect reheating the 
piece to overcome this tendency to crack, due to various 
uneven heats the steel may have received. 

In order to overcome this tendency, the die should 
be reheated in a uniform manner to a temperature that 
allows the various portions to conform to any strains 
in the piece. This may be accomplished by placing the 
die in the fire, turning it occasionally, in order that it 
may be uniformly heated, and heating until moisture 
applied to the surface forms steam. This method when 
applied to large pieces is not apt to result in the center 
of the piece being heated as hot as the outside. Con- 
sequently better results will follow if the die is placed in 
a kettle or tank of boiling water (212 ) and left there 
until heated uniformly throughout. If the die is large 
this will necessitate leaving it in the water at the boil- 
ing point for several hours, as it takes longer to heat 
a large piece of steel throughly than we realize. It 
pays to be very careful about these little points, as these 
dies are often expensive. 

Hardening Long Articles. 

Most hardeners dread hardening long, slender 
articles, on account of the uncertainty attending the 
operation, so far as results are concerned. If the 
article is a reamer or similar tool, having teeth on the 
outer surface, it will not require as great an amount of 
heat as though it were a solid piece. In any case, 
however, do not heat any hotter than is necessary to 

*54 



Proper way to harden long articles. 

accomplish the desired result, always remembering 
that even heats are the secret of success wmen heating- 
steel for hardening. If the tools are hotter on one side 
than the other, unequal contraction must take place ; 
consequently, the article will be crooked. 

When hardening long reamers and similar tools, it 

is necessary that the 

WmnO 1111 

Right neat should be uniform 

and as low as possible. 
It must be the same 
on each side. If one 
side be a low red and 
the opposite side a 
bright red, and it is 
quenched in the bath, 
it is sure to come out 
crooked. A piece of 
this description must 
be dipped in the bath 
in as nearly a vertical 
position as possible, as 
shown in Fig. 72, in 
order to cool both 
sides uniformly. If 
it be dipped at very 
much of an angle, as 
shown in example marked ' 'wrong, " it will surely spring, 
on account of the uneven contraction of the two opposite 
sides. It is necessary to work such pieces up and 
down in the bath, changing the location occasionally in 
order to avoid the effects of the steam generated. 

These may seem like unnecessary precautions, but 
the results obtained will show that it is worth while 




^////////////////////////////■y/^^^^ 



The Deny Coliatd Co. 

Figure 72. Proper method for dipping 
lcng articles. 



155 



Advantages of heated baths. 

observing them as thoroughly as possible. It's the 
little things that count in successful hardening and 
tempering. 

Condition of the Bath. 

If the tool is of a design that makes springing a 
possibility when the article is quenched, it will be 
necessary to warm the contents of the bath consider- 
ably, the degree to which it should be heated depend- 
ing on the shape of the tool and the temper of the steel 
used. Excellent results are many times obtained with 
a bath heated to a temperature of ioo° to 150 . 

The writer has had excellent results when harden- 
ing articles of this description by placing them in 
tubes one inch larger inside than the piece to be 
hardened. It should be placed in the center of the 
tube, the space between the article and the tube being 
filled with charred leather. The ends should be stop- 
ped and sealed with fire-clay. The tube is then placed 
in the fire and given a uniform heat for a period that 
insures the article being evenly heated to the desired 
temperature, when it may be removed from the tube 
and plunged in a warm bath of brine or the citric acid 
solution. 



Hardening Taps. 



It is necessary to take into consideration the design 
of the tool, the steel used, and the nature of the work 
to be done by the tap. If the tool is very long and it 
is necessary to harden but a small portion of the length, 
it is not necessary to heat it any farther up than the 

i«6 



The hardening of taps. 

length which requires hardening. In such cases it is a 
comparatively simple job. 

When a long tap requires heating and hardening 
its entire length, it is necessary to devise some way of 

uniformly heat- 
ing the piece. 
It is also neces- 
sary to quench 
in such a man- 
ner that all por- 
tions will cool 
as uniformly as 
possible, to 
avoid unequal 
contraction, 
thus preventing 
springing or 
cracking. 

When hard- 
ening taps, care 
should be exer- 
cised that the 
teeth are heated no hotter than the refining heat, 
or they will be brittle. If heated hotter than nec- 
essary, it must have the temper drawn very low, or 
the teeth will snap off when used. If the temper is 
drawn low, as described, the tap is too soft to perform 
its full share of work. When hardening tools having 
teeth or projections, it is essential that the heat be the 
lowest possible. It is advisable to heat in a muffle 
furnace or enclosed in some receptacle to remove it 
from the products of combustion in the furnace and 
from oxidation by the action of the air. When it 




?«««<'««<'«&& 



MM 



mmMWtA 



Supply Pipe 

Figure 73 



O^zp 



The Derry Collard Co. 



Bath for hardening taps. 



157 



Bath for hardening taps. 

reaches a low, uniform heat, dip in the bath of water 
or brine, preferably the latter. Work up and down 
rapidly, to bring the contents of the bath in contact 
with the teeth; or, better still, use a bath as shown 
in Fig. 73, having inlet pipes on opposite sides of the 
tank, these pipes being perforated, as shown. It is 
advisable to have the piping so designed that the 
upright perforated pipes may be placed against the 
side of the tank or moved toward each other, in order 
that the jets coming out of the holes may strike the 
object with sufficient force to drive the steam away, 
thus allowing the liquid to act on the steel. 

Long taps give best results if packed in a tube 
with carbon, in the form of charred leather, as de- 
scribed in hardening reamers. When it has reached 
the proper uniform hardening heat, it may be hardened 
by immersing in the form of bath represented in Fig. 
73. If a bath of this description is not at hand, very 
satisfactory results may be obtained by dipping in an 
ordinary bath of the desired temperature, and revolve 
the piece rapidly in the bath to insure uniform results. 
This will in a measure imitate the bath mentioned. 

A bath of brine, or the citric acid solution, give 
excellent satisfaction for hardening tools of this descrip- 
tion. Unless the tap is of large diameter, do not use 
a cold bath. 

Hardening Small Taps, Reamers, 
Counterbores, Etc. 

When small articles of this description are hardened 
in great quantities, it is necessary to devise means 

158 



Muffle furnace for heating taps. 

whereby they may he hardened cheaply, yet the work 
must be done in a satisfactory manner. Various 
methods are employed to accomplish this, and one of 
the most successful methods that has come to the 
writer's attention consists of a furnace made with a 



wmMMmMmm/Mwmmh 



P. 



Muffle 



Fire Box 



r ssssssssssSSS/SSSSMS/S/S/SS//sssss/ss. 



Ash Box 



"~ :':',' . ------- "~ -'-' 



'■;.■■..-■■;, ■■;,:. , ,t~t : :_ 



Smoke 
Pipe 



,r 



^ 



OO^DD 



The Derry Collard Co. 



Figure 74. Muffle furnace for heating taps. 



muffle. The heat was furnished by burning illuminat- 
ing gas, or it may be designed to burn coal. The 
muffle was made as shown in Fig. 74. Cleats are cast 
on to the Avails of the muffle, which in this case was 
cast iron. On these cleats shelves were placed, and 
on these shelves the pieces to be hardened were heated. 
It was necessary to turn the pieces over occasionally to 
insure uniform results. 

When a piece was heated to the proper tempera- 
ture, it was taken by means of a pair of tongs and 
dropped into a bath, which consisted of a tank having 



J 59 



Bath for hardening taps and reamers. 

several tube-shaped pieces of wire netting, as shown in 
Fig- 75- The tubes were slightly larger inside than 
the diameter of the largest part of the tool being 
hardened. Tubes of various sizes were used, the 
size depending on the diameter of the tools to be 
hardened. The tank had a supply pipe coming up 




The Derry Collard Co. 



Figure 75. Bath for hardening taps and reamers. 

from the bottom. This was connected with a supply 
tank overhead. A pump was used to force the water 
into the supply tank. It was possible to use a bath 
of clear water, brine, or any favorite hardening 
solution. In this case, the bath consisted of the citric 
acid solution, described under "Hardening Baths." 
It was kept at a temperature of about 6o°. As fast 
as the pieces were heated to the desired temperature, 
they were taken with tongs and dropped into one 
of the tubes, the cutting end being down. They 



160 



How to brighten taps to show color. 



passed down through the tubes on to an incline, and 
then into a catch pan, as shown. The distance the 
pieces traveled in the bath was considered when 
designing- it. It was found by experiment that the 
largest piece to be hardened would cool below a red 
heat in falling a distance of two feet in the bath. To 
make satisfactory results a certainty, the depth of the 

part of the tank 
through which the 
pieces passed was 
made 36 inches. If 
the tools had struck 
the bottom and 



Figure 76. 

Grinding to show 

temper color. 




turned on their side before the red had disappeared 
from the surface, they would have, in all probability, 
sprung ; but, as it was, excellent results were obtained. 
When taps are brightened, in order that the temper 
colors may be visible, it is not advisable to use a piece 
of emery cloth on a stick or round file, as is often done, 
because unless the operator is extremely careful, he is 
apt to cut away the cutting edge of the teeth, thus 
rendering the tool unfit for use. If possible, use an 
emery wheel of the shape of the groove, as shown in 
Fig. 76. It is not absolutely necessary to use a fixture, 
as the tap may be held in the hands for brightening. 



161 



Other ways of heating taps. 

In this way, not only is the steel brightened, so the 
colors may be readily seen, but the cutting edges are 
ground sharp, and any burrs thrown up between the 
teeth are ground away. 

When but a few taps are to be tempered, it is pos- 
sible to heat them sufficiently in a gas jet or the flame 
of a Bunsen burner ; sometimes the flame of a candle 
is used when the article is very small, as in Fig. 77. 
With a blowpipe, a hot flame can be produced. 

When the taps are made in quantities suffi- 
ciently large, it is much more economical to 
draw the temper by placing in a kettle of oil, 
gauging the temperature with a thermometer. 

The amount necessary to draw the temper 
of a tap in order to get desired results, de- 
pends, as with most 
other cutting tools, on 
the steel used, the heat 
given when hardening, 
and the use to which they are to 
be put. Very small taps that are 
to be used by hand may be left 
harder than those intended for The Derr y' Collard Co - 
use in a screw machine. Taps Fi s ure 77- One way to 
used by hand should be drawn eat sma taps ' 

to deep straw or brown color, while those used on 
screw machine work need drawing to a deep brown, 
and in some cases to a purple. 

Half Round Reamers. 

These should be heated very carefully in a pipe or 
muffle furnace to the lowest heat possible to harden. 

162 




Method for cooling half-round reamers. 



When dipping in the bath, the reamer should be in- 
clined somewhat from a perpendicular position, the 
heavier portion being on the lower side, as shown in 
Fig. 78, to avoid a tendency to spring. The contents 
of the bath should be heated as warm as is consistent 
with good results, as this will help keep it straight. 

Should the ream- 
er spring somewhat 
in hardening, it 
may be straight- 
ened by reheating 
and exerting a 
pressure on the 
convex side. 

If the projection 
has been left on the 
end, as shown in 
Fig. 79, the reamer 
may be placed be- 
tween centers and 
straightened, as 
represented else- 
where. 
Should it be a reamer having ?io center at the 
small end, it may be placed on two V blocks, as shown 
in Fig. 80. Apply heat by means of a gas jet, spirit 
lamp, or any other means to the lower side, heat until 
oil placed on the surface commences to smoke. Now 
apply pressure at P, on top side. When it has beer, 
sprung the proper amount, cool by means of wet 
waste. 

The possibility of straightening reamers and sim- 
ilar work means such a saving in many shops that it 

163 




Figure 78. Proper method for cooling 
half-round reamers. 



Hardening milling cutters. 

will pay to have special attention paid to it, as crooked 
tools of any kind cannot do accurate work. It will 
pay to rig up fixtures especially for this, as the saving 
is far greater than the cost. 

Small, half-round reamers should be drawn to a 
full straw, or a brown color for most work. 



Hardening Milling Machine Cutters. 

As most shops have at least one milling machine, 
and many shops hundreds, there are probably more 
cutters hardened for this class of work than for any 
other. 

In hardening this class of tools, it is necessary to 



The Derry Collard Co. 

Figure 79. Half-round reamer. 

have them hard enough to cut the metal being 
machined, yet tough enough to stand up under the 
strain to which it must be subjected. 

Milling machine cutters should be hardened at a 
lower heat than a solid piece of the same size. The 
teeth, being slender and projecting from the solid 
body, take heat very readily. When possible, tools of 
this description should be annealed after a hole some- 
what smaller than the finished size has been drilled 
and the tool blocked out to shape in order to overcome 
the tendency to crack from internal strains. If it has 
not been possible to do this, or if for any reason it has 

164 



Care in heating milling cutters. 

not been considered advisable, the cutter may be heated 
to a low red and laid to one side and allowed to cool 
until the red has disappeared, when it may be reheated 
and quenched. It is always better, however, to anneal 
after blocking out if it can be planned so as to take 
the time necessary to do this. The results are more 
satisfactory in every way. 

It may be well to again caution the reader in regard 
to the heats. The teeth of this form of tool being thin, 
are apt to absorb heat faster than one realizes, and as 
a consequence, they become too hot. If a cutter is 




The Derry Collard Co. 

Figure 80. Straightening a half-round reamer. 



overheated, it will not do as much nor as satisfactory 
work as though properly heated ; but should the teeth 
by any carelessness become overheated, do not quench 
at that heat, thinking no one will know the difference. 
While it is possible to misrepresent the condition of 
the heat when describing it, the texture of the steel 
always tells the truth in regard to what the operator 
has done with it when in the fire. Neither is it a good 
plan to hold it in the air and let it cool until the color 
shows about right, because it is hotter inside than on 
the outside ; and then again, the grain will be as coarse 

165 



How to cool milling cutters. 



as though it were dipped at the higher heat. It should 
be allowed to cool off and then heated to the refining 
heat and quenched. 

When this form of tool is ready to harden, place it 
on a wire, bent as shown in Fig. 81. The wire should 
be large , x enough to hold the cutter without 
bending, \\ but not much larger, as it should 
not impede \ the circulation of the fluid through 
the hole of the \\ cutter. Neither should any con- 
siderable sized \\ piece of steel rest against the 
side of the cutter, \\ as the action of the bath 
would not be uni- \v form if it were kept away 
from some portions \, of the piece. The cutter 
should be worked \\ around w T ell in the bath 
until the teeth are hard, \\ when it may be re- 




and left until cold. 

held over a fire 

move any ten- 

strains. The 

quired amount. 




moved and plunged in oil 
It should then be taken and 
and heated sufficiently tc re- 
dency to crack from internal 
temper may now be drawn the re 

A method in use 
in many shops, con- 
sists in dipping the 
cutter in a bath of 
water having one or 
two inches of oil on 
the surface. The 

cutter is passed down through the oil into the water. 
Fig. 82 shows a bath of this description. The oil does 
away with the first sudden shock, which results when 
hot steel is plunged into cold water, and as a small 
portion of the oil adheres to the teeth, especially in the 
corners where the teeth join the body of the material, 

166 



Figur 



The Derry Collard Co. 



i . Proper way to cool 
milling cutters. 



Drawing temper of milling cutters. 

the action of the water is not as "rank" as would 
otherwise be the case. Where the teeth are long or 
the mill is of irregular contour, it is advisable to heat 
the water somewhat. Water or brine, heated luke- 
warm, works fully as well as though cold on tools of 
this description and is not as likely to crack them. 
When the outline is very irregular and the tool is made 
of high carbon steel, the writer has had excellent suc- 
cess using a bath of brine heated to 8o° Fahr. The 
idea that a bath must be as cold as possible has prob- 
ably ruined more steel than we realize. 

Drawing Temper of Milling Machine 
Cutters. 



MI|III||I!MI! 



I || 



mimi 



dimi 



ion !i 



Mi'i'iiniini 

<l!i lj Mill 



iWatec 



A method in very general use for drawing temper 
of milling machine cutters, consists in placing the 
hardened cutter on an 
iron plug of the form 
shown in Fig. 83, the 
plug having been pre- 
viously heated suffici- 
ently to draw the tem- 
per of the cutter. 

The plug, when 
heated, should not fill 
the hole in the cutter. 
In order to heat the 
cutter uniformly, it 
should be turned con- 
stantly on the plug. 

It is, of course, necessary to brighten the backs 

167 



f famz^^MZ2mz%MM@MMzm 



The Kerry Collard Co. 

Figure 82. Oil and water bath for 
milling cutters. 



Heating milling cutters on a plug. 

of the cutter teeth in order that the temper colors 
may be readily discerned. 

The writer has had best results by holding the 
cutter over a fire, or a hot plate, and warming the 
circumference to a degree that made it impossible to 









The Derry Collard Co. 



Figure 83. Plug for heating milling cutters. 



hold the hand on it, previous to placing the cutter on 
the plug. It was then placed on the plug and turned 
constantly until the proper temper colors showed, 
when it was plunged in oil to prevent its getting too 
soft. 

The object attained in heating the outer surface 
first, was that the heat given was sufficient to make 
the steel at this point somewhat pliable; whereas, if 
the cutter had been placed when cold on the red hot 
plug, the cutter absorbing the heat would tend to 
expand the steel toward the outer, rigid surface. If 
this expansion should prove, as it does many times, to 
be greater than the steel could stand, cracks would 
result. 

The amount of heat necessary to give a milling 
machine cutter when drawing temper can not be stated 
arbitrarily. It is desirable to leave it as hard as possi- 

168 



Hardening shank mills. 

ble, and yet not have it too brittle to stand up when 
in use ; consequently, it should not be heated any hot- 
ter than necessary when hardening. It should not be 
plunged in a bath of extremely cold fluid, neither 
should it be checked in cold water when the temper 
has been drawn sufficiently. 

While it is not considered advisable by many 
mechanics to make cutters of this description of a high 
carbon steel, the writer's experience has convinced 
him that better results are obtained by using a high 
carbon steel extremely low in phosphorus, and rising 
extreme care in the heating. Then quenching in a bath 
of warm brine, 8o° to ioo° Fahr. 

For ordinary work, a faint straw color (43 o°) gives 
best results, although it may be necessary at times to 
draw to a full straw color, 460 . 

A kettle of oil, heated to the desired temperature, 
furnishes an ideal method of tempering cutters of this 
description. This method has been fully described 
under the proper section on pages 121 and 122, and 
should be carefully considered in connection with tools 
of this character 

Hardening Shank Mills. 

The percentage of carbon necessary to give the 
best results, depends on the make of steel. For ordin- 
ary work, however, a steel having 1 % per cent, gives 
good results. 

The methods employed in heating and quenching 
shank mills when hardening, depend in a measure on 
the form of the mill and the custom in the individual 
shop. . Mills of the form shown in Fig. 84, may be 

l6y 



Best way to harden shank mills. 

heated to a uniform low red heat for a short distance 
above the teeth, stopping the heat in the necked portion, 
marked a. In some shops it is the custom to leave 
the shank quite a little larger than finish size in order 
that it may be turned to size in the lathe and fitted to 




a 



Figure 84. How to. harden shank mills 

the collet or spindle after hardening. In such cases it 
is necessary to leave the shank soft its entire length. 
In other shops it is the custom to turn the shank nearly 
to size before hardening, leaving on just enough to 
allow for grinding to a fit and remove any untruth 
resulting from springing in hardening. If it is neces- 
sary to leave the shank soft its entire length, care 
should be exercised in heating and dipping in the bath 
that the shank is not hardened in the least. If it is to 
be ground to a fit, the same care is not necessary, 
although greater care must be exercised in grinding if 
the shank is hard for a short distance and the balance 
is soft ; but if careful when taking the finishing cuts on 
the grinder, no trouble need be experienced. If the 
cutter is made as represented in Fig. 85, it will be 
necessary, in order to harden the teeth the entire length 
in a satisfactory manner, to harden the shank for a 
short distance. 

When hardening a cutter of the description shown 

170 



Treatment of holes in shank mills. 

in Fig. 86, having a recess of considerable depth in the 
end, much better results will be obtained if it is dipped 
in the bath with the hole uppermost, as shown in Fig. 
87 — that is, provided it is necessary to harden the walls 
of the hole. If this were not desirable, then it would 
be safest to fill the hole with fire-clay, mixed with 
water, to the consistency of dough, and the cutter 
dipped as shown on next page. If the hole was not 
filled and the cutter was dipped in the bath with the 
hole down, the steam generated would drive the water 
away from the teeth at end ; and furthermore, the 
steam would very likely cause the thin walls to crack. 





X 



irzs 



Figure 86. Shank mills. 

When hardening cutters of the form shown in Fig. 
88, known as T slot cutters, it is necessary to harden 
the entire length of portion necked below size of 
shank for several reasons. When the neck portion is 
slender, this is necessary, in order to strengthen this 

171 



Treatment of T slot cutters. 

portion so it will not spring or twist off when the cutter 
is in operation. If the cutter is of a size that makes 
the necked portion large and strong enough to resist 
the cutting strain, it might not appear at first thought 
necessary to harden this. But as it n is gener- 
ally made but a few thousandths of an inch 
smaller than the slot it travels in, it will, if left 
soft, become roughed up by the fine cast iron 
chips, which are liable to get between the walls 
of the slot and 
the stem. Con- 
sequently, it will 
be readily seen 
that in most cases 
it is advisable to 
harden the entire 
length of the 
necked portion. 

If there is 
considerable dif- 
erence between 
the size of the 
cutting portion 
and the shank 
of the tool, the 
cutter should be 
made, if possible, 
with a fillet in the 




The Derry Collard.Co. 



Figure 87. Proper method for 
treating shank mills. 



corner, as shown at a, in sectional view of Fig. 89. If, 
however, this precaution has not been taken, or it has 
not been possible to do it, a piece of iron wire may be 
wound around, as shown at b. This wire being red- 
hot when the cutter is dipped in the bath, has the effect 



172 




Figure 88. 



The Derry Collard Co. 

T slot cutter. 



Fillets for T slot cutters. 

of keeping the contents of the bath away from the 
sharp corner until the larger and smaller portions of 
the mill have become hardened to a degree, thus reduc- 
ing the liabil- 
ity of cracking 
at this point. 
When the cut- 
ter has been 
heated to a low 
red, it should 
be plunged into a bath of water or brine from which 
the chill has been removed ; work around well in the 
bath until it is of the same temperature as the bath, 
when it may be removed and the temper drawn. 

If it has not been possible to heat the cutter in a 
muffle or in a piece of pipe or other receptacle, it will 
be found an excellent plan to have a strong solution of 
potash and water, which should be heated quite warm. 
Before the cutter is heated, 
it may be plunged into the 
potash solution. Place it 
in the fire and heat to the 
proper hardening temper- 
ature and plunge in the 
hardening bath. The 
effect of the potash is to 
cause any thin scale of oxide which may have formed on 
the surface to drop off the instant the tool touches the 
bath. If this scale adheres to the piece, it has a tend- 
ency to rise in the form of a blister when in contact 
with a cool liquid, and consequently it keeps the con- 
tents of the bath from acting on the steel directly 
underneath. 




b 

Figure 89. Fillets for 
T slot cutters. 



173 



Drawing temper of T slot cutters. 

When drawing the temper of a tool of this descrip- 
tion it is necessary, in order that the necked portion be 
as strong as possible (especially if it is slender), to 
draw it to a purple or even a blue color, while the cut- 
ting teeth need drawing to a straw color. 

It is surprising to one not thoroughly posted in the 
effects of different degrees of heat on steel to find how 
hard a cutter of this kind may be left if it was properly 
heated when hardened. This is best seen by compar- 
ing with one that was heated a trifle too hot, yet not to 
a degree that is generally considered harmful to the 
steel. In the case of the cutter properly heated — that 
is, to the refining heat — it may be left when tempering 
at a faint straw color, while if given a trifle more heat, 
it is necessary to draw it to a full straw, a difference 
of 30 of heat, and a vast difference in the amount of 
work it will do between grindings. In order to suc- 
cessfully draw the temper, the necked portion may be 
placed in the flame of a gas jet, a Bunsen burner, the 
flame of a spirit lamp ; or, if none of these are avail- 
able, and it is necessary to use a blacksmith's forge for 
all work of this description, a piece of sheet iron having 
a hole in it may be placed over the fire. A jet of flame 
will come through the hole, which may be made to 
strike the necked portion. In this way the desired 
temper may be obtained. 

Hollow Mills. 

When articles having a hole running part way 
through them, as, for instance, the hollow mill shown 
in Fig. 90, are to be hardened, it is advisable to dip 

174 



Hardening nollow mills. 

them in the bath, with the opening uppermost, as re- 
presented in Fig. 91. If the mill were dipped with the 
opening down, it would be almost impossible to get 
water to enter the hole for any considerable distance, 





Figure 90. A hollow mill. 

as the steam generated would blow the water out. As 
a consequence, the walls of the hole would not harden, 
and the steam would in all probability cause the steel 
to crack. 

Then again, best results will follow if the frail end 
is not chilled until after the heavier, solid portions have 
contracted somewhat. If the lighter portions are chil- 
led and contracted before the heavier ones, the tend- 
ency is for the heavier parts, which are stronger than 
the lighter, to pull them into conformity with them- 
selves, and as the steel is hard and rigid, it must crack. 
While this principle is explained elsewhere in this 
work, it seems wise to show the adaptability of this 
peculiarity of steel to pieces of this description. 

When making articles having holes, as shown, if 
the piece is to be hardened, the liability of cracking 
will be lessened if the stock at the end of hole is left, 
as shown in Fig. 92. If, however, the piece is made 



'75 



Tepid water for hardening hollow mills. 



with a sharp corner, as shown in Fig. 93 > it is advisable 
to fill in this sharp corner with fire clay, or graphite, 
in order that there may be no pronounced difference in 
the contraction of the two portions. 

When hard- 
ening pieces of 
this character, it 
is , generally 
speaking, good 
practice to use a 
bath of tepid 
water or brine. 

When it is con- 
sidered desirable 
to harden a piece 
a certain dis- 
tance, and no far- 
ther, and the fa- 
cilities for heat- 
ing do not allow 
of heating ex- 
actly the right 
distance, it is 
necessary to dip 
in the bath with 
the teeth down. 
In order to over- 
come the tendency of the steam to blow the water 
from the hole, a small vent hole is drilled through the 
wall of the piece, as shown in Fig. 94. If this hole is 
large enough to allow the steam to escape, good re- 
sults will follow if a bath is used having a jet of water 
coming up from the bottom, as, by this means, water is 

176 




The Derry Collard Co. 



Figure 91. Method for hardening 
hollow mills 



Various types of hollow mills. 



forced into the hole. However, the operator should 
bear in mind that it is never good practice to have 




Figure 92. 
Hollow mill with 
rounded corners. 




The Derry Collard Co. 

the hardening stop at a shoulder, either inside or out- 
side of a piece of steel. Where possible, stop the 



Figure 93. 

Hollow mill with 

sharp corners. 



hardening somewhat short of the shoulder, but if 
this does not meet the requirements, harden a trifle 



Figure 94. 

Hollow mill with hole 

to allow escape 

of steam. 



beyond the shoulder. This may seem like a little 
thing to bother about, but it generally means the dif- 
ference between a good job and a poor one, and it's 

177 




Hardening thin articles. 

one of the little points that count in making a success- 
ful hardener. 

Thin Articles. 

Thin articles, as screw slotting- saws, metal slitting 
saws, etc., may be hardened between two plates whose 
faces, are covered or rubbed with oil. If reasonable 
care is exercised in the operation, they will be very 
straight. 

It is essential, in order to get good results, to heat 
the pieces on a flat plate. They should be heated no 
hotter than is necessary to accomplish the desired result. 
When at the proper heat, the saw may be taken by a 
pair of tongs, of the form shown in Fig. 95, and placed 
on a plate whose face is covered with lard, sperm 
or raw linseed oil. The advantage derived from using 
tongs of this description is, the saw is held by the por- 
tion near the hole, rather than by the teeth, as would 
be the case if a pair of the ordinary style were used. 
In that case, the teeth grasped by the tongs would not 
be of the same temperature as the balance of the saw; 
and, as a consequence, the hardening would not be 
uniform. Another plate, whose face has been treated 
in a similar manner, may be placed on top of the saw 
and held there until the saw is cold. It is necessary to 




Figure 95. 
The Deny Coilard Co. Tongs for holding flat plates. 

place the top plate in position as quickly as possible, 
after the saw has been placed on the lower plate. 

If the saw should become chilled before the upper 

178 



Method of cooling flat plates. 

plate is placed on it, it will spring somewhat, and the 
upper plate cannot straighten it. Should it be sprung 



a 



■V/////////////////////////////////////////////////// /////////■ 




Figure 96. Device for cooling 
thin, flat work 



The Derry Collard Co. 



very much, the pressure applied to the upper plate 
will, in all probability, break the saw, as it would be 
hard and unyielding. 

If many pieces of the description mentioned are to 
be hardened, it is advisable, for the sake of economy, to 
make a special device for chilling the work, as when 
two plates are used, it is necessary to have the services 
of two men, one to handle the saws, and one to work 
the movable plate. If the number of pieces to be 
hardened does not warrant an expensive apparatus, 
two flat plates may be used, drilling two holes in each 
plate, as shown in Fig. 96. The holes in the lower 
plate should be a driving size for ^ inch wire, while 
those in the upper plate should be -^ inch larger than 



179 



Devices for hardening thin plates. 



the size of the wires. A cord should be attached to 
the upper plate, as shown. This cord should pass 
over a pulley and return to a treadle. The operator, 



\m 



0~^Q= j 

|9M|iQ ) I (D~l 

0=0= 




The Deny C.ollaid Co. 

Figure 97. Device for hardening between plates. 

by using this device, can handle the saws and operate 
the plate very nice^. 

In Fig. 97 a device is shown for hardening thin 
pieces between plates, which consists of the base a, 



Necessity for keeping jaws of plate holders cool. 

and slide b, to which are attached jaws cc. Through 
the jaws are several wires for the work to rest on when 
it is placed between the jaws. The side is operated by 
the treadle e, which is connected to the base and slide 
by the brackets ff. The device is supported by the 
legs as shown. The advantage derived from using a 
fixture having the jaws standing in a vertical line, as 
shown, is, the piece of work is not as liable to chill while 
closing the jaws, as would be the case were the jaws 
in a horizontal position. 

If the work is hardened in large quantities and the 
jaws show a tendency to get hot, they may be cast hol- 
low and a water pipe connected with each, providing 
an outlet on the opposite side. In this way a circula- 
tion of water may be kept up through the jaws, thus 
keeping them cool at all times. In order to insure a 




The Derry Collard Co. 

Figure 98. Cooling plate mounted on springs. 



uniform circulation of the w r ater, it will be necessary 
to have the inlet pipe at the lower edge, on one end of 
the jaw, and the outlet pipe on the upper edge at oppo- 
site end. The outlet pipe should be carried far enough 
to do away with any liability of any of the water get- 
ting on the surfaces of the jaws that were to come in 
contact with the pieces being hardened. 



Cooli 



ng gun springs. 



When saws or other pieces of considerable thickness 
are hardened between plates, it is sometimes necessary 
to provide for a supply of oil around the teeth when 
the plates are in position. In order to do this, it is 
necessary to use 
plates in a horizontal 
position, as shown in 
Fig. 98, having the 
lower plate resting on 
springs, or other ar- 
rangement to keep its upper face above the surface of 
the oil in the pan, until the work has been placed on 
it. The pressure applied by the upper plate must 




Figure 99. Gun spring. 




Figure 100. Method for cooling gun spring shown above 
or other irregular pieces. 

submerge them in the oil in pan to a depth 
insures the teeth being well covered with oil. 



that 



8z 



Drawing temper of slitting saws. 

When drawing the temper of tools of this descrip- 
tion best results can be obtained by putting the pieces 
in a kettle of oil, gauging the heat by a thermometer. 
While the degree of heat necessary to produce the 
desired result can not be given arbitrarily, as very 
much depends on the steel used, the amount of heat 
given when hardening, and the use to which it is to be 
put. But ordinarily, metal slitting saws for general 
jobbing purposes should be drawn to 460 degrees. 
Screw slotting saws, -^ inch thick and under, 525 de- 
grees. If thicker, do not draw as low. 

The method of hardening between plates may be 
applied to pieces having other than flat forms. Take, 
for instance, springs which, in order to maintain a 
given tension, must be of a certain shape ; for example, 
the main spring of a gun, as represented in Fig. 99. 
The form of spring is shown at a, while bb is a pair of 
plates, having their faces formed to harden the spring 
and keep it in the proper shape. It is not generally 
desirable or advisable to use a form when hardening 
springs of this character, but is sometimes necessary. 
The method and amount necessary to draw the temper 
of springs is given under Spring Tempering, and to 
avoid repetition the reader is referred to that section. 
It has seemed necessary to repeat some statements in 
order to show their different applications and to im- 
press them on the mind. 

Screw-Drivers. 

There is probably no one article so generally used 
as the screw-driver that gives so much trouble. In the 
first place, not more than one man in ten understands 
how to properly make the tool, and then but a small 

183 



How to make a proper screw-driver. 



percentage of this one-tenth can harden and temper it 
properly after it is made. 

A screw-driver is better for having been forged to 
shape, provided it is forged properly ; that is, heated 
properly and hammered in a scientific manner. Unless 
one understands these operations well enough to do a 
good job, it is advisable to file or machine one from 
the bar. 

A screw-driver should be made with the end that 
enters the screw 



TT 



\J 

b 



V 



The Derry Collard Co. 

Figure i o i . Styles of screw-driver points. 



slot of an equal 
thickness through- 
out, and to nearly 
fill the slot. At 
times, this precau- 
tion is observed, 
and the portion 
immediately ad- 
joining is made 
much heavier and 
with square corners, as shown at a, Fig. 101. Now, on 
account of the unequality of size of the adjoining por- 
tions, it is a difficult matter to harden and temper 
it uniformly throughout. Then again, the shape is 
such that it must break where the heavy and light por- 
tions adjoin, on account of the unequal strength of 
the two portions. 

Now, a screw-driver, or any tool which must resist 
a bending or twisting strain, must be made in such a 
manner that the tension will be taken up for a con- 
siderable portion of the length of the article, thus 
doing away with a tendency to break at any one point. 
In Fig. ioi, b represents a screw driver made in a man- 

184 



More about screw-drivers. 



ner that apparently, according to some mechanics' 
minds, will just fill the bill. It is symmetrical, that is, 
there are no breaking points ; but look at the end that 
enters the screw slot — it looks more like a chisel than a 
screw-driver. Now, when pressure is applied to this 
form, it, on account of the inclined sides, 
slips out of the slot. It will not hold, so 





Figure 102,. 

One way of testing 

a screw-driver. 



The Der<y Colkrd Co. 



a stick or piece of iron is 
placed on top of it in the 
form of a lever, and one or 
two men hold down on the end 
of this, as shown in Fig. 102, 
and the fellow 
doing the job gets 
a wrench on, and 
yanks. Now, the 
screw-driver is 
subjected to two 
strains instead of 
one. It tries to 
get out of the 
slot, and cannot, 

on account of the power applied above. It is also 
subjected to torsional strain from the direct pull of 
the wrench, and it breaks. Now, if it is made of the 
form represented at c, Fig. 10 1, and hardened and tem- 
pered properly, there will be very little danger of it 
breaking from any ordinary usage. 

When heating for hardening, give it the lowest heat 
that will produce the desired result. Remember, hard- 

185 



Hardening taper mandrels. 

ness is not the desired quality ; it will not be called on to 
cut metals, it must simply resist strain or pressure, 
consequently toughness is the quality to be sought. 
Articles hardened in cold water do not show this 
quality to such a degree as those quenched in oil, so 
it is advisable to use oil as the cooling medium when it 
will answer. If oil will not answer, then heat the 
water. If it is a comparatively small screw-driver, 
heat the water nearly to the boiling point. The larger 
the article, the less heat it will be found necessary to 
give the water ; but in no case, unless the steel is low 
in carbon and the screw-driver very large, should cold 
water be used. 

The amount necessary to draw the temper varies 
with the percentage of carbon the steel contains. If it 
is made of ordinary tool steel, it may be heated until 
hardwood sawdust catches fire from the heat in the 
steel, or until a fine shaving from a hardwood stick, 
made by drawing the stick across the edge of the screw 
driver, catches fire, as noted before. When the proper 
temper shows, it may be quenched in warm oil or hot 
water, never in cold water. 

While screw-drivers may seem like a small affair, 
hardly worth while thinking much about, the frequency 
with which they are used and the time lost in regrind- 
ing after breakage, make them quite an important tool 
in any shop. Then, too, the damaged screw heads 
must be counted against them. 



Tap 



er Mandrels, 



When it is necessary to harden taper mandrels 
made of tool steel, it is necessary to provide some means 
of uniformly heating the article. One end, being of a 

186 



Hardening counterbores. 

greater diameter than the other, has a tendency to heat 
slower. Owing- to this fact, it will be necessary to 
heat slowly. When it has reached the desired heat, 
which should be uniform throughout, grasp by the 
small end with a pair of tongs and immerse in a bath 
of water or brine, which has a jet coming up from the 
bottom. When it ceases singing, remove and plunge 
in a tank of oil, allowing it to remain until it is cooled 
to the temperature of the bath. It should then be 
reheated to remove the tendency to crack from internal 
strains. 

Counterbores. 

The toolmaker or designer should, when designing 
tools that are to be hardened, avoid, as far as possible, 
sharp corners between portions of different sizes. If 
a counterbore is made as shown in Fig. 103, the presence 





L 
\ 


K-T- % 




1 




The Durry CoJlard Co. 

Figure 103. Counterbore with square corners. 

of sharp corners is an invitation for the steel to crack 
from unequal contraction at these points. If the 
corners are rounded (filleted), as shown in Fig. 104, the 
tendency to crack is almost entirely eliminated. 

Many times serious trouble arises from countersink- 
ing center holes too deeply in articles that are to be 
hardened. Fig. 104 represents a sectional view of 
countersinking in pilot, which is deep enough for all 

187 



Proper temper for counterbores. 

practical purposes, while in Fig. 103, the countersink- 
ing is so deep that there would be a great tendency to 
crack when hardening. When articles of this de- 
scription are countersunk too deeply, it is advisable to 
fill the hole with fire-clay before placing it in the fire. 
This plan, of course, would not work satisfactorily in 
the case of mandrels, arbors, and similar tools, whose 
centers must be hard in order to resist wear. 

Heat to the lowest uniform red that will cause the 



/ 



%~% 



\ 




Figure 104. Counterbore with filleted corners. 

article to harden, dip in a bath of lukewarm brine, 
hardening part way up the portion necked below size 
of shank. 

When drawing the temper of counterbores, apply 
the heat at shank end, allowing it to run toward the 
cutting end of teeth. 

The proper amount to draw the temper depends on 
the character of the work to be done, the design of the 
counterbore, etc. It was formerly the custom to draw 
the temper to a degree that made it possible to sharpen 
the cutting edges by filing with a sharp, smooth-cut 
file. If the counterbore is made of the design shown 
in Fig. 104, it may be sharpened by grinding on the 
face (a) of cutting tooth with an emery wheel, thus 
making it practical to leave the tool much harder than 
would otherwise be the case. 

A very common mistake when making tools of this 



Hardening mandrels, arbors, etc. 

description is to stamp any distinguishing marks on the 
tool when finished, thereby springing it; and unless 
this fact is noticed, the hardener will be blamed for it. 
All stamping should be done before the important portions 
are to size. 

When hardening counterbores having inserted pi- 
lots, it is advisable to fill the pilot hole with fire-clay, in 
order to prevent the water entering. If the design is 
such that the tool is liable to crack when quenched, it 
should be dipped in the bath with the teeth uppermost. 
The contents of the bath should be warmed to reduce 
the liability of cracking. 

Hardening Mandrels, Arbors, Etc. 

Mandrels, arbors, and similar articles, which are to 
be hardened, are generally made of any piece of tool 
steel which comes handy. Now, it is a fact that tools 
of this description give a great deal of trouble when 
hardened, unless the operator is quite skillful. As the 
only reason for hardening a mandrel is to give it a hard 
surface and make it as stiff as possible, the desired 
result may be obtained by using a steel that is not high 
in carbon. Take, for instance, a steel containing ^ 
per cent, or one per cent, carbon. As good results can 
be obtained as if a steel containing i J^ per cent, carbon 
were used, while the article would not be as liable to 
crack or spring as if a high carbon were used. 

When making articles of this description, steel 
somewhat larger than finish size should be selected. 
The outside should be turned off and the piece annealed. 
After annealing, it may be machined to grinding size 
and then hardened. 

When hardening, a fire large enough to heat the 



Caution about small fire. 

piece uniformly should be used, and the piece turned 
frequently to insure good results. A mistake some- 
times made in heating pieces of this description con- 
sists in using a fire too small to accomplish the desired 
result. One end and the center is heated, the end is 
reversed and the opposite end is heated. The first 
end, in the meantime, has cooled to a degree that 
makes it unsafe to quench the piece in the bath. So 
the second end is heated hotter than it should be, with 
the idea in view that the piece will again be reversed 
and the over-heated end will cool to the proper harden- 
ing heat, while the temperature of the opposite end is 
being raised to the desired heat. When it is taken 
from the fire, it is in the worst possible condition to 
harden; the center is too hot, one end is apparently 
about the right temperature, but the interior is not hot 
enough. The opposite end is possibly at about the 
right heat, but the interior is too hot. In this condi- 
tion it is immersed in the bath and violent strains are 
set up, which result in the piece being cracked or 
sprung out of shape. Now, this is not at all right, yet 
it is so commonly practiced that the writer feels it 
necessary to caution the reader against a practice which 
is so radically wrong. 

If obliged to use an ordinary forge, build a fire 
large and high enough so the piece may be uniformly 
heated ; turn frequently ; keep the piece well buried in 
the fire to prevent oxidation of the surface. When the 
steel reaches a low red heat, take it from the fire, 
sprinkle some pulverized cyanide of potassium on the 
surface. Place in the fire and bring to a uniform red 
heat, which must be a trifle higher than if there were 
teeth or projections on the surface, as, these being light, 

190 



Mandrel centers must be very hard. 

would cool more quickly than a solid piece. If possi- 
ble, use a bath having a jet of liquid coming- up from 
the bottom. If it is a mandrel, it should be grasped 
by one of the ends with a pair of tongs of the descrip- 
tion shown in Fig. 86. This insures hardening the 
body of the mandrel, and also allows the contents of the 
bath to have free access to the upper center, which 
would not be the case if a pair of tongs of the ordinary 
description were used. 

It is essential that the centers of a mandrel be very 
hard. For this reason a method of quenching in the 
bath should be used that insures the centers in both 
ends hardening. 

If it is considered best to draw the temper of the 
ends in order to avoid the corners chipping or the ends 
breaking, it is not advisable to make them as soft as 
the dead center of the lathe, which is usually drawn to 
very deep straw or brown color. The object attained 
in having the ends of a mandrel harder than the lathe 
center is that in case of wear, the center, being the 
softer of the two, will probably wear rather than the 
centers of the mandrel. 

The piece should be worked up and down in the 
bath until it is of the same temperature as the contents 
of the bath, when it may be removed and heated some- 
what to overcome the tendency to crack from internal 
strains. It should be held in a vertical position when 
dipping, in order to avoid springing. 

Better results will follow if the piece is placed in a 
piece of pipe or tube when heating. 

A very excellent method consists in placing the 
article in a piece of gas pipe, which is closed at one 
end. The hole in the pipe should be about one inch 

191 



Hardening grooved rolls. 

larger in diameter than the piece to be hardened. Fill 
around it with granulated charred leather, having the 
mandrel in the center of the hole in the pipe, and the 
ends should not be within ^ inch of the ends of the 
pipe. Fill the pipe with the charred leather; place a 
loose-fitting piece of iron in the open end of pipe, and 
seal with fire-clay. When this is dry, the pipe may be 
placed in the fire and remain until the article is uni- 
formly heated to the proper temperature, when it may 
be taken from the pipe and quenched, as described. 

Still better results may be obtained if the piece is 
kept at a low red heat for a period of several hours, 
the time depending on the size of the piece. If y 2 inch 
diameter or under, i ^ hours will be found sufficient. 
If larger, run correspondingly longer. When it has 
run sufficiently long, the piece may be removed from 
the tube, grasped by the tongs, as shown, and plunged 
in a bath of raw linseed oil, working up and down 
rapidly in the bath. This method receives further 
consideration in section on Pack Hardening. 

Hardening Grooved Rolls. 

When grooved rolls or similar articles are to be 
hardened, it is necessary to heat very uniformly. The 
projections, as shown in Fig. 105, have a tendency to 
heat faster than the balance of the roll. Should they 
become hotter, the projections will be very liable to 
crack or break off when quenched. As it is necessary 
to heat slowly in order to get uniform heats, the piece 
would be liable to oxidation on its outer surface, which 
is exposed to action of the products of combustion in 

192 



Cooling in vertical position. 

the fire and the air. if heated in an open fire. If small, 
it may be heated in a tube ; if too large for this, it may 
be covered with tne carbonaceous paste described in 
section on Methods of Heating. When the article has 



8 



Ths Derry Collard Co. 

Figure 105. A grooved roll. 



reached the desired uniform heat, it should be plunged 
in the bath in a vertical position. On account of the 
peculiar shape of the piece and the tendency of the 
steam generated, the contents of the bath should be 
agitated from the outside toward the center of the bath. 

A method that gives very excellent results when 
hardening articles of this description is to use a bath 
having pipes coming up at the sides of the tank, as 
shown in Fig. 106. There should be a sufficient number 
of openings in these pipes to supply a generous quantity 
of water in order to produce the desired result. The 
water should be under sufficient pressure to project the 
contents of the bath against the piece being hardened, 
with enough force to drive the steam away, so the 
water can readily come in contact with the heated 
surface. 

If the pieces are short and not too large, they may 
be heatf d in red-hot cyanide, dipping in a bath of the 
form described 

If it is not necessary to harden very deeply, the 
193 



Hardening bath for grooved rolls. 

article may be removed from the bath when hardened 
sufficiently and placed in a tank of oil, leaving them in 
the oil until the steel is uniformly cooled to the tem- 




The Derry Collard Co. 



Figure 1 06. Bath for hardening grooved rolls. 



perature of the oil. It is extremely important when 
hardening pieces of this description that they be 
reheated as soon as possible after removing from the 
bath to overcome the tendency to crack from internal 
strains. The longer they remain under strain, the 

194 



Hardening the walls of holes. 

more likely they are to crack later without any apparent 
eause. Every mechanic can recall cases of this kind. 




Figure 107. Piece with hole through center. 



Hardening the Walls of Holes. 

A peculiarity of a cylindrical piece of steel is that, 
when hardened, it is liable to become oval in shape. 
This is especially true of pieces having holes running 
through their centers, as shown in Fig. 107. When it 

is possible, or is 
considered advis- 
able to grind the 
piece inside and 
outside after hard- 
ening, the amount 
it goes out of shape 
need not in any way interfere with the utility of the 
tool, provided there has been a sufficient allowance of 
stock made for grinding. 

If, however, there 
is no means at hand 
for grinding the piece 
after hardening, it be- 
comes necessary to 
harden in a manner 
that does away with 
the tendency of the 
piece going out of 
shape or the hole con- 
tracting very appreciably. This may be accomplished 
in the case of such articles as ring gauges, reducing 




Figure 108. Gauge with hole 
through center. 



I9S 



No necessity to "season" for a year. 




Figure 109. 
Method of 

cooling 
ring gauges. 



dies, and any tools which do not require hardening 
on their outer circumference, if proper care is taken. 

When gauges of this description (as shown in Fig. 
108) are hardened by the ordinary methods, it is neces- 
sary to rough-grind them to within a few thousandths 

of an inch of finish size and 
lay them away to "season" 
or "age." After laying for 
a few months or a year, they 
are finished to size by grind- 
ing and lapping. It is not 
necessary to observe this 
precaution except in the case 
of gauges that are to be used 
in making very accurate meas- 
urements. 

Now, it is not always de- 
sirable to wait a 
year after a piece 
of work is hard- 
ened before 
grinding to size 
and using. In 
order to over- 
come the tend- 
ency of altera- 
tion of sizes and 
shapes as the piece ages, it may be hardened in a 
manner that gives the walls of the hole sufficient 
hardness to resist wear, yet leaving the circumfer- 
ence soft. This can be accomplished by heating 
the piece very carefully to the required heat and 
placing in a hole a trifle larger than the outside of the 

196 




How to close a worn die. 

piece. Now place a piece of metal having a hole some- 
what larger than the hole in the gauge on top of the 
piece, as shown in Fig. 109. A stream of water may 
now be turned on in such a manner as to readily pass 
through the hole, thus cooling the walls and hardening 
them. The balance of the stock, being protected, does 
not harden. The walls of the hole being hard and in- 
flexible do not yield as the piece grows cold. And as 
the outside portion of the piece is hot and yielding, it 
does not necessarily contract in the direction of the 
hole, thus reducing the tendency of alteration of size 
of the hole. 

Dies used for re- 
ducing the size of 
gun cartridges, Fig. 
no, and similar 
pieces, are hardened 
by this method, and 
give excellent re- 
sults, because the 
outside, being soft, 
will have no tend- 




Figure no. Die for reducing cartridges. 



ency to break from the pressure exerted when the 
die is in use. 

As there is very little tendency of alteration of size 
and shape of the hole, it can be lapped to size without 
grinding. In case it is not to be ground, there need 
be but a small allowance for lapping, provided the hole 
is smooth and straight. 

As is customary when dies of this description be- 
come worn, they may be closed by heating red-hot and 
being driven into a taper hole. This diminishes the size 
of the hole in the die, which may then be reamed to size 



97 



Hardening where holes are near edge. 

and rehardened. In order to get good results, it is ad- 
visable to anneal the steel after closing in, or the mole- 
cules of steel will not assume their proper relations 
when hardened. 



Articles with Holes Near One Edge. 

When hardening articles having holes near the edge, 
extreme care must be observed, as the unequal con- 
traction occasioned by the form of the piece will make 
it very liable to crack. A piece of the form shown in 

Fig. in, represents an 
example of the form 
mentioned. While 
such a piece could be 
hardened by the pack- 
hardening process 
with.no liability of its 
cracking if it were 
quenched in a bath of 

Figure ill. Piece with hole near edge. ^ {j . wouM ^ ^ way g 

be considered advisable to use this method, so it be- 
comes necessary to heat the article in some form of fire, 
and quench in water. 

The piece should be heated very carefully and no 
hotter than is necessary to accomplish the desired re- 
sult. It will be necessary to use the utmost care in 
heating, because if the thin portion of stock between 
the hole and the circumference of the ring were heated 
any hotter than the balance of the piece, it would 
surely crack at this point. 

When dipping in the bath, the heavy portion should 




How to cool pieces with holes near edge. 

enter the bath first, the thin portion should be upper- 
most in order that it may enter last. 

If it is not essential that the walls of the hole be 
hard, it may be filled with fire clay, previous to placing 
in the fire. If treated according to this method, the 
danger of cracking is reduced to the minimum. 

A method employed very successfully in some shops 
when hardening articles of this description, consists in 

Figure 1 1 2. Method for 

holding piece with 

hole near edge. 



bending a piece of wire in the form of a hook. This 
hook is heated red hot on the bent end, and when the 
article is at a uniform heat, the red hot end of the hook 
is inserted in the hole near the edge, as shown in 
Fig. 112, and the article immersed in the bath. The 
heavy portion will, of course, enter the bath first, the 
wire being red-hot will prevent the thin portion cooling 
as rapidly as it otherwise would. The size of the wire 
must be determined experimentally; that is, if many 
pieces are to be hardened, the size of wire that gives 
best results should be used, but in no case should it 
fill the hole when the pieces are cold. 

The bath should be warmed somewhat in order to 
reduce liability of cracking. 

Wood -Working Tools. 

There are many methods used in hardening tools 
used for cutting wood, the different methods varying 

199 



Hardening wood-working tools. 

according to the nature of the steel used and the use to 
which the tool is to be put when finished. The more 
common method is to heat in an open fire and plunge 
in water, drawing the temper until the brittleness is 
reduced to a point that makes it possible for the tool 
to stand up when in use. By this method, it is neces- 
sary to draw the temper quite low in order to get a de- 
gree of toughness that enables the tool to stand up well. 

A method that is practiced in many shops is to heat 
in a mufHe furnace or in a tube, hardening in a bath 
of water having oil on its surface, as shown in Fig. 82, 
the depth of oil depending on the desired amount of 
hardness. Some hardeners claim to be able to gauge 
the amount of hardness by the depth of oil to a nicety, 
that makes it unnecessary to draw the temper after 
hardening. The writer cannot vouch for this claim, 
as he has never seen it done when hardening wood- 
working tools, but has been able to accomplish it when 
certain kinds of iron-working tools were hardened. 

Another method consists in heating the tool in a 
crucible of red-hot lead, or in a crucible of red-hot 
cyanide of potassium, dipping in a bath of oil, to which 
has been added a quantity of alum. The exact amount 
cannot be stated, as he has found it to vary when 
applied to hardening steels of various percentages of 
carbon. The use to which the tool is to be put when 
hardened, has a great deal to do with the composition 
of the bath. 

As brittleness is not a desirable quality in wood- 
working tools, it is necessary to harden in a manner that 
insures toughness in the hardened product. For this 
reason it is not advisable to use a bath of cold liquid 
of any kind. 



Mixture for hardening wood-working tools. 

If the cutters are light on the cutting portions, the 
bath may be heated considerably, the temperature de- 
pending on the shape and size of the tool and the steel 
used in its construction. 

Various animal or vegetable oils are used for quench- 
ing tools of this description, either separately or mixed 
with varying proportions of tallow. Melted tallow is 
many times used with success, heated to a temperature 
that gives good results when applied to the individual 
piece of work. The amount necessary to draw the 
temper depends on circumstances and can not be arbi- 
trarily stated, but it is generally found to be between 
a brown and a dark blue color. 

A method employed in some shops when hardening 
wood cutting tools consists in heating to a low red 
and plunging in a mixture of molten lead and tin in 
the following proportions : Lead, 7 parts ; tin, 4 parts, 
which melts at about 440 Fahr. 

The cutters are heated to a low red and plunged in 
this mixture at the temperature mentioned, allowed to 
cool for a short time, then removed and cooled in water. 
They will be found to be exceedingly tough, and capa- 
ble of holding their edge in a satisfactory manner. 

Unless this method is used in a painstaking manner, 
it had better not be tried, as anything but satisfactory 
results will follow. 

If many cutters are to be hardened, it will be found 
necessary to gauge the heat of the bath by use of a 
thermometer. 

Fixtures for Use in Hardening. 

In order to attain certain results, it is necessary at 
times to make fixtures for holding the work. These 



An example of hardening fixtures. 

fixtures are designed to protect certain portions of the 
piece of work from the action of the contents of the 
bath. 

The writer was at one time in charge of work in a 





The Deiry Collard Co. 
Figure 113. A hard piece to harden. 



shop manutacturing bicycles. In order to accomplish 
a desired object, the axle cones, which had formerly 
been made of machinery steel, were made from a high 
grade of tool steel. The front axle cone was of the 




The Deiry Collard Co. 



Figure 114. Device for hardening piece shown in Figure 113. 



shape shown in Fig. 113. It was necessary to harden 
the beveled portion extremely hard, in order to resist 
wear. It was found very difficult to harden this 
portion without hardening the flange. If this were 
hardened, it showed a tendency to break when in the 
wheel, as it was very thin. 

In order to harden the bevel and leave the flange 



The Genesis of pack hardening. 

soft, a fixture was made, as shown in Fig. 114. The 
cone was heated in a crucible of red-hot lead. When 
it reached the desired temperature, the cover of the 
fixture was raised and the cone taken from the lead by 
means of a wire hook made for the purpose. It 
was placed in the fixture, as shown, the cover lowered, 
and the fixture immersed in a bath of water, working- 
it around well until the cone was cold, when the fixture 
was inverted over a tank of boiling water, and the cone 
dropping into this and remained until a sufficient 
quantity was in the catch pan, Fig. 45, to warrant 
emptying it. This tank was found very valuable, as 
it furnished a means whereby the strains incident to 
hardening could be removed, and at the same time the 
temper was drawn sufficiently. 



Pack Hardening. 



CO 

When articles which are small or thin are heated to 
a red and plunged in oil, they become hard enough for 
most purposes, but not as hard as if immersed in water. 
Articles hardened in oil seldom crack from the effects 
of cooling, as the heat is not absorbed as quickly as if 
water were used, neither are they as likely to spring. 

The fact that articles quenched in oil showed no 
tendency to crack, and very little liability to spring, 
has led the writer to make exhaustive experiments in 
perfecting a method whereby articles which gave 
trouble when hardened by ordinary methods might be 



Pack hardening prevents cracking. 

hardened in oil and produce a surface as hard as if it 
were heated red-hot and plunged in water. The re- 
sults have been more gratifying than were ever dream- 
ed of before trying. It is not claimed that this method 
was originated by the writer. It was suggested by a 
man in his employ, who had seen it practiced with 
varying results in a shop where he formerly worked. 

The fact that milling machine cutters, punch press 
dies, and similar articles, could be treated in such a 
manner that they might be hardened in oil without 
danger of cracking, led to experimenting, which re- 
sulted in a method whereby tools could be hardened 
with absolutely no danger of cracking. The tendency 
to spring was also reduced to the minimum. Unexpected 
results were accomplished in some ways, for it was 
found by experience that milling machine cutters could 
be run at a periphery speed, two, and in some cases four, 
times as great as when a similar cutter made from the 
same bar was heated red-hot and plunged in water. 
Punch press blanking dies would do from six to ten 
times the amount of work as when hardened by meth- 
ods formerly used. 

It was also found extremely satisfactory when ap- 
plied to taps and screw thread dies, because the tendency 
to alteration of pitch was reduced to the least possible 
amount. Neither would they change so far as diametri- 
cal measurements were concerned. Gauges hardened 
by this method gave results fully as satisfactory as other 
articles hardened in a similar manner. Long reamers, 
stay-bolt taps, and similar tools, have been hardened 
by the thousands and shown results more than satis- 
factory. 

Tool steel is made with a sufficient quantity of 

204 



Never use bone in pack hardening. 

carbon to harden in a satisfactory manner and accom- 
plish the results intended when the tool is made. To 
make steel with a higher percentage of this hardening 
element, and put it on the market, would be folly, as 
the average man hardening steel would treat it the 
same as the ordinary tempers are treated, with the re- 
sult that the tools made from it would be ruined when 
hardened. 

Now, tool steel may be treated with carbonaceous 
materials when red-hot, with the result that the sur- 
faces will be extremely hard if the article is quenched 
in oil. The depth of the hardened surface depends on 
the length of time the article is subjected to the car- 
bonizing element. In order to accomplish the desired 
result, the piece of work must be packed in a hardening 
box with the carbonaceous material; the top must be 
closed with a cover slightly smaller than the opening 
in the box, and the space between the cover and sides 
of the box covered with fire-clay. This operation is 
familiarly known as sealing. Sealing the box has the 
effect of preventing the gases escaping. It also pre- 
vents the direct heat of the fire from entering the box, 
as that would be very injurious to the steel. Then 
again, the oxygen in the air is excluded from the box, 
or, if present in a degree, does not oxydize the surface 
of the piece, as it is taken up by the packing materials 
in the box. 

It is very necessary when charging steel by the 
process under consideration, that a carbonizing ma- 
terial be used which contains no elements injurious to 
tool steel. For this reason no form of bone should 
ever be used, as bone contains a very high percentage 
of phosphorus, and phosphorus, when present in tool 



About boxes for pack hardening. 

steel, has the effect of making it extremely brittle. The 
processes the steel maker puts the steel through in 
order to remove injurious impurities is one reason of 
its high cost as compared with the ordinary cheap 
grades of steel. The lower the percentage of phos- 
phorus, the more carbon it is safe to have in the steel ; 
so it will readily be seen that any process which results 
. in an addition of this harmful impurity should never 
be used. The writer has used a mixture of equal parts, 
by measure, of granulated charcoal and granulated 
charred leather in most of his work for the past nine or 
ten years with the best results ; although in exceptional 
cases, where extreme hardness was desired, charred 
leather alone was used. 

The work is packed in a hardening box. This box 
may be either wrought iron or cast iron. Best results 
are claimed by some when wrought iron boxes are used. 
But the writer has never in practice been able to notice 
any difference, so he has used cast iron boxes altogether 
for the past eight years, as they are cheaper and more 
readily obtained. The work should be placed in the 
box in a manner that does not allow any of the pieces 
to come within \ x /z inches of the bottom or top of the 
box, or within i^ to i^ inches of the sides or ends, for 
two reasons. If they are placed too near the walls of 
the box, they are affected by every change of tempera- 
ture in the furnace. Then again, cast iron has a great 
affinity for carbon, and will extract it from a piece of 
tool steel if it comes in contact with it. If one end of 
an article, packed as described, comes in contact with 
the walls of the box, the piece will not harden at that 
point, or, if it does, it will not be as hard as the balance 
of the piece. And, as a chain is no stronger than its 

206 



How to pack for hardening. 

weakest link, so a hardened tool is no better than its 
softest spot, provided it is on any cutting portion, be- 
cause, when that dulls, the whole tool must be ground. 

This method of pack hardening is not only a means 
of getting good results, but when work is hardened in 
large quantities, it is a much cheaper method than that 
ordinarily used, because quite a number of pieces may 
be packed in the box at a time. Or, if the furnace used 
is of sufficient capacity, several boxes maybe heated at 
the same time. 

When packing work in the hardening box, place 
about 1^2 inches of packing material in the bottom, then 
lay a row of work on this, being careful that no pieces 
come within ^ inch of each other, or within i^ inches 
of the walls of the box. Cover this row of work with 
packing material to the depth of ^ inch, put in another 
row of work, and continue in this way until within i y^ 
inches of the top of the box. After covering each row 
of work with the packing material, it should be tamped 
down lightly to insure its staying in place. When the 
box is filled to within the distance of top mentioned 
(ij4 inches), the balance should be filled with packing 
material, the cover put in place and sealed w T ith fire- 
clay mixed with water to the consistency of dough, 
and allowed to dry before placing in the furnace. 

Before the articles are packed in the box, a piece of 
iron binding-wire should be attached to each piece of 
work in such a manner that the article may be removed 
from the box and dipped in the bath by this means, 
unless the piece is too heavy to be handled in this man- 
ner, in which case it must be grasped with a pair of 
tongs. The wires should extend up the sides to the 
top of the box and hang over the edge, in order 

207 



Figure 115. The wrong way to 
pack harden. 



Pack boxes with similar articles. 

that the operator may readily see them when removing 

the articles from the box. If several rows of work are 

placed in the box, it is necessary to place the wires in 

a manner that allows the different rows to be readily 

distinguished. As it is necessary to draw the pieces on 

the top row first, each succeeding row should be drawn 

in its order, because if an article were drawn from the 

bottom row first, it would probably draw one or more 

of the pieces located above along with it. As a conse- 

quence they 

would lay on 

the top of the 

box exposed to 

the action of the 

air, and would 

cool perceptibly 

while the first 

piece was being 

quenched in the 

bath. For this reason it is advisable to draw the 

pieces in the top row first, as described. 

As the length of time a piece of steel is exposed to 
the carbonaceous packing material after it is red-hot 
determines the depth of hardening, articles packed in 
a box should all be of a character that need carbonizing 
alike, or some pieces will not receive a sufficient depth 
of carbonizing and others will receive too much. Know- 
ing this, one may select the articles accordingly, pack- 
ing those requiring charging for one hour in one box, 
those requiring two hours in another, and so on. A 
little experience will teach one the proper length of 
time to give a tool of a certain size to accomplish a 
given result. 




•The Derry Collard Co. 



208 



Boxes for pack hardening. 

Attention must be paid to the shape of the piece 
when packing in the box. If it is long and slender, it 
should not be packed in such a manner that it will be 
necessary to draw it through the packing material, as 
shown in Fig. 115, or it will surely spring from doing 
so, it being red-hot, and consequently easily bent. If 
but a few pieces of this character are to be hardened, 
it would not be advisable to procure a box especially 




Figure 116. Box for pack hardening. 



adapted to it. In that case the articles could be packed 
two or three in a box. When they have run the proper 
length of time, the box should be removed from the 
furnace, turned bottom side up on the floor, provided 
the floor is of some material that will not catch fire. 
The piece of work may be pulled out lengthwise from 
the mass, and in that way all danger of springing is 
done away with. 

If, however, quite a number of pieces are to be 
hardened, it is advisable to procure a box adapted to 
pieces of this description. This may be done by adopt- 
ing a design opening at the end, as shown in Fig. 116. 
This may stand on end with the opening uppermost 
while packing the pieces. If a furnace of the design 



How to tell when heated. 



shown in Fig. 1 1 7 is available, it should be used, as the 
box can stand on end. If this form of furnace is not 
at hand, the box may be placed on its side in any fur- 
nace large enough to receive it. If necessary to use a 
furnace where the box must lay on its side, it will be 
advisable to provide some way of fastening the cover 
in place. This may be done 
by drilling a ^ inch hole on 
opposite sides of the box and 
running a rod at least Yt of 
an inch smaller than the hole 
across the face of the cover, 
Fig. 1 1 8, before sealing with 
fire-clay. This rod can easily 
be removed when the articles 
are ready for immersion in 
the bath. 

In order that the exact 
time at which the work be- 
comes red-hot may be ascer- 
tained, it will be necessary 
to use test wires. Several % 
inch holes may be drilled 
near the center of the 



cover, a 



_3__ 

1 <> 



inch wire 



run through each of 
these holes to the bot- 
tom of the box, as 
shown in Fig. 26. When 
the work has been in 




The Derry Collard Co. 

Figure 117. Furnace for use in 
pack hardening. 

the furnace for a sufficient length of time to become 
heated through, according to the judgment of the 
operator, one of the test wires may be drawn and its 





The length of time work should be run. 

condition noted. If it shows red-hot the entire length, 
note the time. If not, wait a few minutes (say, 15 
minutes) and draw another wire. When one is drawn 
that shows the proper temperature, time from this. 

The length of time the pieces should be run cannot 



The Derry Collard Co. 

Figure 1 1 8. Method of fastening cover in place. 

be stated arbitrarily, as the character of the work to be 
done by the tool must, in a measure, determine this. 
However, if the pieces are ^ inch diameter, and are to 
cut a soft grade of machinery steel, one hour may be 
found sufficient. If a harder surface is required, it is 
necessary to run somewhat longer (say, 1% hours). 
When the work has run the required length of time, the 
box may be removed, the cover taken off, and the ar- 
ticles taken out one at a time and dipped in a bath of 
raw linseed oil. When the articles are long, it is ad- 
visable, if possible, to use a bath having a perforated 
pipe extending up two opposite sides of the tank, as 
shown in Fig. 119. A pump should be connected with 
the oil in the bath, pumping it through a coil of pipe 
in a tank of water and forcing back into the tub through 
the upright perforated pipes shown. This method 
insures evenly hardened surfaces, as the jets of oil 
forced against the sides of the article drive the vapors 
away from the piece, thus insuring its hardening. It 
is necessary to move the work up and down and to turn 



How to treat milling cutters. 

it quarter way around occasionally in order to present 
all sides to the action of the oil. 

When milling machine cutters, or similar tools 
having projections, are to be hardened by this method, 
they should be packed in the box, using the packing 



Figure 119. Bath for use in 
pack hardening. 




The Deny Collard Co. 



material mentioned. Previous to placing the cutters 
in the hardening box, a piece of iron binding- wire should 
be attached to each cutter and allowed to project over 
the edge of the box. Test wires should be run dowm 
through the holes in the cover, as shown in Fig. 26. 
The length of time the cutters should run is determin- 
ed by the character of the work they are to do ; but for 



Milling cutters needing no tempering. 



ordinary milling, a cutter 3 inches diameter, if of the 
ordinary design, should run about 3 hours. 

If the teeth are heavy, of the style known as form- 
ed mills, Fig. 120, they should be run 4 hours after they 
are red-hot. When the box is removed from the fur- 
nace, the cutters may be removed one at a time, placed 
on a bent wire of the form shown in Fig. 81, and im- 
mersed in the oil, working them around well until all 
trace of red has disappeared, when they may be dropped 
to the bottom of the bath and left until cold. 

A milling machine cutter of the form shown in Fig. 
120 will not as a rule require tem- 
pering. The teeth may be left 
as hard as they come from the 
bath, but those of the ordinary 
form of tooth should have the tem- 
per drawn. This may be done by 
the method described under Hard- 
ening and Tempering Milling 
Machine Cutters, or, if there are 
many cutters, a saving of time 
will result if the articles are 
placed in a kettle of oil and the 
temperature gauged by a thermometer, drawing them 
to 430 degrees. 

Punch press blanking dies give excellent satisfac- 
tion if hardened in this manner. The die is packed in 
a box. Test wires are run down through the opening 
in the die to the bottom of the box. When drawing the 
wires to test the heat, do not draw them way through 
the cover. After observing the heat, place the wire 
back in its original position. A wire can be raised from 
time to time, the amount of heat observed and the wire 




Tlie Deny Col lard Co. 

Figure 120. Formed 
milling cutter. 



213 



Treatment of blanking dies. 

returned. In this way the operator can tell from time to 
time the exact temperature of the piece being heated, 
and as the same laws governing- the heating of steel in 
the open fire apply when heating to harden by this 
method, it is advisable to keep the heats as low as pos- 
sible ; for steel treated by this method will harden in 
oil at a lower heat than if treated in the ordinary way 
and hardened in water. 

Blanking dies for the class of work usually done 
on punch presses (if they are i inch to i y 2 inches thick) 



Figure 121. Bath for 
blanking dies. 




should run about four hours after they are red-hot. 
At the expiration of that time the box may be removed 
from the furnace, the die grasped by one end with a 
pair of tongs and immersed endwise down into a bath 
of raw linseed oil. It is a good plan to have the bath 
rigged as shown in Fig. 121. A pipe is connected with 
the tank near the top, and runs in a coil through a tank 
of water. A pump draws the oil from the tank through 
the coil, and forces it back into the bath, as represented. 



214 



Handling of dies and taps. 



The inlet pipe may be so situated as to cause the oil to 
circulate with considerable force through the bath. This, 
striking the face 
of the die, passes 
through the 
opening, insures 
good results. If 
no means are pro- 
vided for the cir- 
culation of the 
oil, the die may 
be swung back 
and forth in the 
oil, and it will 
harden in a satis- 
factory manner. 
Forming and 
bending dies, if 
hardened by this 
method, must be run longer, and heated somewhat 
hotter, yet not hot enough to injure the steel. 

Pack hardening- fur- 




The Derry Collard Co. 

Figure 122. One method of packing 
snap gauges. 




nishes a method 
whereby taps may be 
hardened without 
altering the pitch very 
perceptibly; neither 
will the diametrical 
measurements be 
changed, provided the 
blanks were annealed after blocking out to shape, and 
by this method the teeth are made exceedingly hard 
without being brittle. A tap from one to two inches 



Figure 123. Another method of packing 
snap gauges. 



215 



Pack hardening for gauges. 

in diameter should be run about two hours. It should 
be worked around rapidly in the bath, in order that the 
teeth may be hardened. For general machine shop 
work, taps do not require the temper drawn as low 
as if they were hardened by heating red-hot and 
plunging in water. Generally speaking, 430 degrees 
(a faint straw color) is sufficient, provided a low heat 
was maintained in the furnace. 

This is an ideal method of hardening gauges and 
similar work, as the liability of cracking is eliminated 
and the danger of springing is reduced to the minimum. 
If the gauge is of the plug or ring form, it is not neces- 
sary to allow as great an amount for grinding as would 
otherwise be the case, as there is little danger of 
springing. 

When hardening snap gauges, especially if they 
are long, it is advisable to pack as represented in Fig. 
122, provided a box deep enough is at hand. If obliged 
to pack in a box so that the gauges lay lengthwise in 
the box, they should be so placed as to have the edges 
up and down, as shown in Fig. 123, thus doing away 
with the tendency to spring when they are drawn 
through the packing material. 

Articles of a form which betokens trouble when 
hardening can, if proper precautions are take*n, be 
hardened by this method in a very satisfactory manner. 
Take, for instance, the shaft shown in Fig. 124. This 
was made of J/% per cent, carbon crucible steel, and turned 
within a few thousandths of an inch of finish size. It 
was packed in a mixture of charred leather and char- 
coal, and subjected to heat for 1 y 2 hours after it was 
red-hot. It was then dipped in a bath of raw linseed 
oil, heated to a temperature of 90 . It was found 

216 



Treating difficult subjects. 

upon being tested between centers to run nearly 
true. 

The designer does not always take into consideration 
the difficulties which may be encountered when a piece 
of irregular contour is hardened, consequently we some- 
times run across articles which call for serious study 
on the part of the hardener when the article reaches 
him. Then again, such articles are many times made 



The Derry Collard Co. 



Figure 124. A peculiar piece to harden. 

of a high carbon tool steel, when alow grade steel would 
answer the purpose as well, and not cause nearly as 
much trouble. 

At one time the writer was called to a shop where 
they were experiencing all kinds of trouble in an attempt 
to harden a gauge of the description shown in Fig. 125. 
As it was not practical to grind the interior of this gauge 
with a grinding machine, it was necessary that it should 
retain its shape when hardened. In order to accom- 
plish this, the gauge was surrounded with a mixture of 
fire-clay, to which was added sufficient hair (obtained 
from a plasterer) to hold it together. It was moistened 
with water to the consistency of dough. The hole in the 
gauge was filled with finely granulated charred leather. 

It was then placed in a small hardening box,in the 
bottom of which was placed 2 inches of granulated wood 

217 



How the "teaser" was hardened. 

charcoal. The box was filled with charcoal, the cover 
placed in position, and sealed with fire-clay. 

The box was subjected to heat for one hour after 
the contents were red-hot, this being ascertained by 
means of the test wires, as described. The gauge was 

then taken from 
the box, the leather 
removed from the 
hole, and a jet of 
raw linseed oil 




Figure 125. 
A "teaser" for 

hardening. 



The Derry Collard Co. 



forced through the hole until the piece had cooled off. 
The walls of the hole were very hard, and the gauge 
was found by test to have retained its shape. The 
coating of fire-clay prevented the exterior hardening 
of the piece, thereby eliminating the tendency to 
spring or go out of shape. The walls of the hole, 
hardening first, retained their shape, and the balance, 
being red-hot, conformed to this portion. 

While it would be impossible to enumerate the 
various articles of irregular contour that may be hard- 
ened by applying this principle — namely, protecting 
the portions that do not require hardening, by the use 
of a mixture of fire-clay and water, adding sufficient 
hair to hold it together — it can safely be said that many 
thousand dollars' worth of tools are ruined annually, 
which might have been saved had this precaution been 
observed. 



218 



Pack hardening for mandrels and arbors. 

As this process of charging the surface of the steel 
with carbon is a process of cementation, it is necessarily 
slow. When extremely high carbon steel is used in 
making tools, it is considered advisable by some to use 
hoofs and horns as packing material rather than leather. 
At times it is not considered desirable to subject 
the articles to heat for so great a length of time. In 
such cases it is necessary to treat the surfaces to be 
hardened with some material that will act more quickly 
than charred leather. In fact, at times it is necessary 
to prevent any portion other than the ones to be hard- 
ened from becoming red-hot. 

This can be effected by covering the parts with the 
fire-clay mixture to a considerable depth, applying heat 
to the portions that need hardening. When it is not 
desirable to subject the article to heat for a length of 
time sufficient to charge the steel with the necessary 
amount of carbon to cause it to harden (if it was to be 
carbonized by means of charred leather), excellent re- 
sults may be had by the use of a mixture of 5 parts of 
rye flour, 5 parts table salt, 2 parts yellow prussiate of 
potash, filling the hole or covering the portions to be 
hardened with this. 

Mandrels, or any form of arbor which it is consid- 
ered advisable to harden, will harden in a more satis- 
factory manner by this method than by any that has 
come to the writer's notice. If the article is long and 
slender, do not pack in the box in such a manner that 
they will spring when drawn out ; but if the shape of 
the box is such that this cannot be avoided, the box 
may be turned bottom side up on the floor when the 
articles are ready for hardening, as previously explained. 
If, however, the mandrels are made of the proportions 



How to dip mandrels and arbors. 




usually observed when making- for general shop use, 
there is very little liability of springing when drawing 
them through the packing material. The mandrel may 
be wired as represented in Fig. 126, or it may 
be grasped with a pair of tongs of a form that 
allows the contents of the bath to have ready 
access to the end of piece ; but as tongs of this 
form are not in general use, the wires will 
answer unless the pieces are very heavy. In 
this case it is advisable to procure tongs of 
a suitable shape rather than to have an un- 
satisfactory article when it is finished. As 
stated under Examples of Hardening, it is 
never advisable to hold a mandrel with any 
form of tongs that in any way interfere with 
the hardening of the walls of centers in the 
ends of a mandrel. 

If the work is wired, it should be done 
in a manner that makes it possible to dip 
the mandrel in the bath in a vertical position, 
to avoid any tendency to spring. The wires 
may be grasped by means of tongs which 
close together very nicely, as shown in Fig. 
126, in order that they may not lose their 
grip and the piece fall to the bottom of the 
bath before the red had disappeared from 
the surface. It should be worked up and 
down in the oil until all trace of red has 
disappeared, when it may be lowered to the bottom 
and left until cooled to the temperature of the bath. 

Circular forming tools, especially those having 
long, slender projections and sharp corners, as shown 
in Fig. 127, are safely hardened by this process, as they 




Figure 126. 

How to 
dip in bath. 



Stay-bolt taps and the like. 







Figure 12; 



The Deiry CollarJ Co 

A forming tool. 



can be given any degree of hardness desirable without 
making them brittle. Being solid in form, they must 
be heated for a longer period of time than if there were 
teeth on the surface — as a milling machine cutter. As 
with other cutting tools, the length of time a tool of 
this form should be subjected to heat depends on the 

nature of work to 
be performed by 
it. A tool 4 inches 
in diameter and 2 
inches wide for 
ordinary work 
should run about 
4 hours after it is 
red-hot. If there 
are slender projec- 
tions from the face of the tool, it will be found 
necessary to draw the temper somewhat ; but as a rule 
it should not be drawn as low as if it were hard- 
ened by the methods ordinarily employed. 

The writer has in mind a forming tool of the 
same general outline as the one represented in Fig. 127, 
which gave excellent results when drawn to 350 degrees 
after hardening by the method under consideration. 
It was hard enough to stand up in good shape, and yet 
tough enough to stand very severe usage. 

If the formed surface is of a shape that insures 
strength — that is, if there are no projections — the cut- 
ter should be left as hard as when it comes from the 
bath. 

Stay-bolt taps and similar tools may be packed in 
a box of the proper shape and run for a length of time, 
depending on the size of the piece. They should then 



Precautions to be taken on large work. 

be taken one at a time and immersed in a bath of raw 
linseed oil and worked tip and down in a vertical man- 
ner, moving to different parts of the bath, unless there 
is a jet of oil coming up from the bottom. Or, better 
still, having perforated pipes coming up the sides of 
the bath, as represented in Fig. 119. In either case it 
is advisable to work the articles up and down, to avoid 
the vapors which always have a tendency to keep the 
contents of the bath from acting on the heated steel. 

If the articles are long, a deep tank should be used 
for the bath. If the taps are 24 inches long, there 
should be a depth of 40 inches of oil. If the articles 
are longer, the tank should be proportionally deeper. 

A precaution that should always be observed when 
hardening large pieces of work, when they are to 
be quenched in a bath of oil, consists in protecting the 
hands and arms of the operator to prevent burning 
from the fire, which results when a piece of red-hot 
steel is immersed in oil. This is, of course, simply a 
burning of the surface oil as the steel passes through 
it, but it is liable to flash high enough to burn the 
hands and arms unless they are protected in some 
manner. 

When hardening long articles, it is found much more 
convenient if the tanks containing the cooling liquid 
are so located that the tops of the tanks are nearly on 
a level with the floor — say 12 or 15 inches above it. 

The toolmaker should, when making adjustable 
taps, reamers, etc., of the description shown in Fig. 128, 
leave a portion on the end solid, as shown in Fig. 129, 
to prevent the tool springing out of shape. The hole 
for the adjusting rod should be filled with fire-clay, 
the article packed with the mixture of charcoal and 



How to harden an adjustable reamer. 



charred leather, and subjected to a very low red heat, 
and dipped in raw linseed oil, warmed to about 90 
degrees Fahr. The length of time it should be sub- 
jected to heat after it is red-hot depends on the size, 



S 







>; -E 








-V .-. ■ TW- 1 


f \tfs 



Figure 129 

of reamer 



The Derry Collard Co. 

Solid portion 



Figure 128. An adjustable reamer. 

quality of steel used, and the work it is to do. It 
will vary from i to 2^ hours. The temper may be 
drawn to a light straw or a full straw color. The 
shank, and ends of flutes nearest the shank, should be 
drawn to a blue. When drawing the temper, the 
reamer or tap may be placed 
in a kettle of oil heated to 
the proper degree for the 
cutting edges. The shank 
may be drawn lower in a 
flame, or heat may be ap- 
plied at the shank end by 
means of a flame from a gas jet, Bunsen burner, or 
any other means, allowing the heat to run toward the 
cutting end. After the reamer has been hardened and 
ground to size, the extreme end may be ground off 
enough to allow the slots to extend to the end. 

Dies used for swaging tubing are a source of an- 
noyance when hardened by methods usually employed, 
as the unequal sizes of the different portions cause 
them to spring out of shape, and their shape is such 
that it is next to impossible to grind them in a manner 
that insures satisfaction when they are used. 

Pack hardening furnishes a method whereby this 



Box for heating swaging dies. 

class of work can be made hard enough to do the work 
required of them, and they do not alter in shape enough 
to require grinding. For this reason the extremely 
hard surface, which comes in contact with the contents 
of the bath, need not be removed by grinding. 

When making swaging dies of the description 
mentioned, best results will follow if they are made of 
tool steel of iyi to i % per cent, carbon. Block to shape, 
anneal thoroughly, and finish to size. When harden- 
ing, the dies should be wired and packed in a box, 
as shown in Fig. 130, placing charred leather all 
around the die for a distance of ^ inch to 1 inch. The 
balance of the box 
may be filled with 
packing mixture 
that has previously 
been used. Run 
for about 4 hours 
after they have 
reached a medium 
red heat. It is 
necessary to give 
articles of this description a trifle higher heat than 
if hardening cutting tools made from the same stock. 

As hardness is the required quality, the dies should 
be left as hard as when taken from the bath, which 
should be raw linseed oil at a temperature of about 60 
degrees Fahr. 

A careful study of the pack hardening method 
will help e /ery one handling steel. It often makes 
possible the use of lower grade steels, and it enables 
pieces to be made of any desired shape with the knowl- 
edge that they can be hardened without cracking. 




Tile Derry Collard Co. 



224 



Case Hardening. 



0^=^ ^=^3 



CO 

When wrought iron or machinery steel — especially 
the latter — will answer the purpose as well as tool steel, 
they are generally used. The first cost is less, and it 
can be machined much more cheaply, and in many cases 
it is better adapted to the purpose. 

Machinery steel is made by two entirely different 
processes, namely: the Open Hearth and the Bessemer 
processes. Each method produces steel adapted to 
certain classes of work. There are many grades of 
steel made by each of these processes, these being de- 
termined by the amount of carbon or other elements 
present in the steel. Machinery steel is not only valu- 
able to the manufacturer on account of its low first cost, 
as compared with tool steel, and the ease with which 
it may be worked to shape, but it possesses the quality 
of toughness, and is not so susceptible to crystalliza- 
tion from the action of shocks and blows. A very 
valuable feature is, that by subjecting it to certain 
processes, the surface may be made extremely hard, 
while the interior of the steel will be in its normal 
condition, thereby enabling it to resist frictional wear 
and yet possess the quality of toughness. 

The hardening of surfaces of articles made of 
wrought iron and machinery steel is generally termed 

225 



Case hardening a few pieces. 

"case hardening," and consists in first converting the 
surface of the article to steel, then hardening this steel 
surface. In order to convert the surface to steel, it is 
necessary to heat the piece red-hot, then treat it while 
hot with some substance which furnishes the necessary 
quality to cause the steel to harden when plunged in a 
cooling bath. 

Most machine shops have some means whereby 
they can harden screws, nuts and similar articles. 
Where there is only a limited .number of pieces to 
harden, it is customary to heat the work in a black- 
smith's forge, in a gas jet, or in any place where a red 
heat can be given the piece. When hot, sprinkle with 
a little granulated cyanide of potassium, or some yel- 
low prussiate of potash, or a mixture of prussiate of 
potash, sal ammoniac and salt. If cyanide of potassium 
is used, it is advisable to procure the chemically pure 
article, as much better results may be obtained. The 
reader should bear in mind that this is a violent poison, 
Re-heat to a red and plunge in clear, cold water. When 
there are large quantities of work to harden, this is an 
expensive as well as a very unsatisfactory way. To 
case harden properly, one must understand the ma- 
terial of which the article is made and the purpose for 
which it is to be used — whether it is simply to resist 
friction or wear, or to resist sharp or heavy blows, a 
bending or twisting strain, or whether it is merely de- 
sired to produce certain colors. 

We will first consider the case hardening of work 
that simply needs a hard surface, with nothing else to 
be taken into consideration. Pack the articles in an 
iron box made for this purpose, as shown in Fig. 131. 
The size and shape of the box used depend, as a rule, 

2x6 



Case hardening in a gas pipe. 

on what can be found in the shop. But when results 
are to be taken into consideration, it is advisable to 
procure boxes adapted to the pieces to be hardened. 
It is not policy to pack a number of small pieces, 
which do not require a deeply hardened portion, in a 
large box, especially if it is desirable to have a uni- 
formity in the hardened product, as the pieces which 




Figure 1 3 1. Box for case hardening. 

are near the walls of the box will become red-hot long- 
before those in the center. And as steel or iron 
absorbs carbon only when red-hot, the pieces nearest 
the outside would be hardened to a greater depth 
than those near the center of the box. 

For small articles, where but a few pieces are to 
be hardened at a time, a piece of gas-pipe may be used. 
Screw a cap solidly on one end or plug the end with a 
piece of iron, using a pin to hold it in place. The 
outer end may be closed by means of a piece made in 
the form of a cap to go over the end, or it may be a 
loose-fitting plug held in place by a pin, as shown in 
Fig. 118. When a hardening box of the description 
shown in Fig. 131 is used, the heat may be gauged 
nicely by running test wires through the cover to 
bottom of tube, as shown in Fig. 126. Pack the pieces 
of work in a mixture of equal parts, by measure, of 



227 



How to pack for case hardening. 

granulated raw bone and granulated charcoal mixed 
thoroughly together. Cover the bottom of the harden- 
ing box to a depth of i^ inches with the mixture, 
pack a row of work on this, being sure that the arti- 
cles do not come within % to y 2 inch of each other, 
or within i inch of the walls of the box. Cover this 
with the packing material to a depth of half an inch. 



Testwirei= 
Test wire 



The Derry'Collard Co. 



Figure 132. A method of using test wires. 



Tamp down, put on another layer, and so continue 
until the box is filled to within 1 inch of the top. 
Fill the remaining space with refuse packing material 
left over from previous hardenings, if you have it. 
If not, fill with charcoal or packing material, tamp 
well, put on the cover, and lute the edges with fire- 
clay to prevent as much as possible the escape of the 
gases. This is necessary, as the carbon is given off 
from the packing material in the form of a gas. Then 
again, if there are any openings, the direct heat will 
penetrate these and act on the work in a manner that 
gives unsatisfactory results. 

If the articles are so large that they would not cool 
below a red heat before reaching the bottom of the bath, 
they should be wired, as shown in Fig. 130, before put- 

228 



To case harden many small pieces. 

ting in the hardening box. Use iron binding wire, suf- 
ficiently strong to hold the piece when it is worked 
around in the bath. If the articles are too heavy for 
wiring, we must devise some other way of holding — ■ 
either tongs or grappling hooks. If the pieces are 
small, they can be dumped directly from the box into 
the tank, sifting the work out of the box somewhat 
slowly, so that the 



r\ 



r\ 



Figure 133. 

Bath for case hardening 

small pieces. 




The Derry Collard Co. 



articles will not go 
into the bath in a 
body. If the tank 
is large enough, it 
is a good plan to 
have wires across 
from side to side, 
about 4 inches 
apart in horizontal 
rows. Have the 
rows 3 or 4 inches 
apart. Do not put 
any two consecu- 
tive rows of the wires underneath each other, but in such 
a manner that the work will strike the wires as it passes 
to the bottom of the tank. In striking these wires, the 
work will be separated, and any packing material ad- 
hering to it will be loosened by the jar. The work will 
also be turned over and over, thus presenting all sides 
to the cooling effects of the bath as it passes through. 
These wires can be arranged as shown in Fig. 133 by 
taking two pieces of sheet metal, a little shorter than the 
mside length of the tank, drilling holes in them as de- 
scribed in the arrangement of wires, and wires can be 
passed through these holes and riveted, thus making a 



229 



Details of tank for hardening small work. 

permanent fixture that can be placed in the tank and 
taken out at will. The distance the wires are apart can 
be varied to accommodate the particular kind of work 
that is to be done. They must be far enough apart so 
that the work cannot become lodged on them. 

This simple device does away with the liability of 
soft spots in pieces of work that are case hardened. Do 
not have any wires within 8 or 10 inches of the bottom 
of the tank. Have a coarse screen or a piece of sheet 
metal drilled full of holes somewhat smaller than the 
piece we are to harden. Block it up about 4 inches 
above the bottom, to allow a free circulation of water 
underneath it. This also allows the water to pass 
through it around the work, and the packing material 
will pass through it, giving the water a better chance 
to get at the work. The water inlet should be at the 
bottom of the tank, and we should have an outlet about 
2 inches from the top to allow the surface water to 
escape. The cold water coming up from the inlet at 
the bottom should be turned on before we dump the 
work, allowing it to run until the work is cold. In 
heating the work, any form of furnace that will give 
the required heat and maintain it evenly for a sufficient 
length of time will do. 

The cover of the boxes should have several % inch 
holes drilled in the center, as shown in Fig. 26. After 
putting the cover m place, put pieces of •£% inch wire 
through these holes down to the bottom of the boxes, 
allowing them to stick up an Inch above the cover, to 
enable us to get hold of them with the tongs. The 
boxes may now be put in the fire, and subjected to a 
heat which should vary according to the character of 
the work. The work should be heated to a red, and 

230 



Unsatisfactory to gauge heat by total time. 

for some classes of work it may even be brought to a 
bright red. When it is thought that the work has been 
in the fire long enough to heat through, draw one of 
the wires with a long pair of tongs. If the wire is red 
the entire length, time from then. If not, wait a few 
minutes and draw another, and so on until one is drawn 
that is red the entire length. 

The writer considers this the proper method to 
employ in timing all work being heated in the fire, 
whether it is to be annealed or case hardened, charging 
for hardening by the Harveyizing method, or when we 
are pack hardening tool steel. If the work is timed 
from the time it is put in the fire, the results will be 
uncertain, as the fire is hotter one day than it is another. 
Sometimes the fire acts dead, another day lively, so the 
box is longer in heating at one time than at another; 
but if it is timed from the period when the work com- 
mences to take carbon, the results will be as nearly 
uniform as it is possible to get them, provided the heat 
is uniform, which can be gauged quite closely by the 
eye. Better results can be obtained by the use of the 
pyrometer, although for ordinary work this is not 
necessary. After running the work the proper length 
of time, which varies according to the nature of the 
steel and the purpose for which it is intended (small 
articles, % inch or less, which do not require anything 
but a hard surface, should be run one or two hours 
after they are red-hot), dump into the water. 

If it is desired to have them colored somewhat, 
hold the box about a foot or 18 inches above the tank, 
allowing them to pass this distance through the air be- 
fore striking the water. If we are hardening small 
screws having slots for screw-drivers, and are harden- 



Advice as to use of packing material. 

ing simply to keep the screw-driver from tearing the 
slot, we can use expended bone as packing material — 
i. e. , bone that has been used once before. It will make 
the work hard enough for all practical purposes, yet 
not hard enough to break. If we wish to harden deeper, 
we must run about five hours after the work is red. 
By running sixteen or twenty hours, we can harden to 
a depth of }i inch. In the case of small articles, it is 
best to use a bone not coarser than what is known as 
No. 2 granulated raw bone. When we are to run for 
a long period of time in the oven, we should use a 
coarser grade. 

When it is necessary to harden very deep, it is ad- 
visable to pack the work with coarse bone, letting it run 
from 15 to 20 hours in the fire, then taking out and re- 
packing with fresh material. Work that is allowed to 
run for too long a time with the same packing material 
is very liable to be not only insufficiently carbonized, 
but to be in a measure decarbonized and highly charged 
with phosphorus, which is very injurious to the ma- 
terial we are using. The charcoal used in the mixture 
should, if possible, be the same size granules as the bone. 
The commercial article is much superior to anything 
we can pound and sift, so it is policy to buy it. The 
first cost may seem a trifle stiff, but if account is taken 
of the time it takes to pound and sift a barrel of char- 
coal, it will be found the cheaper article. 

There are many special preparations used in case 
hardening, some of which are excellent for special 
work, while some are good for all kinds of work. 
When we wish to harden deep in a short space of time, 
it is advisable to use bone black in place of granulated 
raw bone. Bone black, or animal charcoal, as it is 

232 



Mixture for use on color work. 



commercially called, is prepared by burning bones in a 
special furnace. It comes in the form of a powder. It 
leaves a finer grain in the work hardened, and it will 
make it stronger than if hardened with raw bone. 
Another form of bone which gives excellent results is 
called hydrocarbonated bone, a form of bone black 
treated with oil so that it gives off its carbon more 

readily than 
either form 
mentioned be- 
fore. It is not 
generally used, 
but for nice 
work it is very 
satisfactory. 

If we wish to 
give a nice color 
to our work, it is 
necessary to 
first polish it 
and be sure it is 
clean when 
packed in the 
hardening box. 
Use the follow- 
ing mixture 
when packing: 




Bath having an air inlet with water, 
for obtaining colors. 



10 parts No. i granulated raw bone. 
2 parts bone black, 
i part granulated charred leather. 
Mix thoroughly before using. The results will be 
much more gratifying, if a pipe which is connected with 
an air pump is run up into the water inlet pipe, as shown 

233 



How to cool case hardened work. 

in Fig. 134. By this means a jet of air is forced into the 
water at the bottom of the tank in such a manner that 
it will be distributed through the whole bath, in order 
that each piece of work may come in contact with it as 
the work passes through the water. 

When articles are hardened by the first process 
mentioned, heating in the fire and treating with cyanide 
of potassium, very nice colors can be obtained by taking 
a piece of gas pipe, putting one end in the bath and 
blowing through it, passing the work through the air 
in the water when we dip it. When the articles are thin, 
and must be very hard, yet tough, it is best to use a 
bath of raw linseed oil. 

If this bath is used, it is advisable to attach a piece 
of iron binding wire to each piece when we pack the 
work, allowing the wires to hang over the sides of the 
box. When we take the box from the fire, the articles 
can be removed from it and immersed in the oil by 
means of the wires. They should be worked around 
well in the bath until the red has disappeared, but in 
such a manner that broad sides are not moved against 
the cool oil, or the articles may spring. By taking this 
precaution, there will be no difficulty in obtaining satis- 
factory results in practically all cases. 

The advent of the bicycle opened the eyes of me- 
chanics to the fact that a low grade steel could be used 
to advantage for many purposes, where formerly it 
would have seemed necessary to use tool steel under 
similar conditions. 

As competition made it necessary to produce a 
machine weighing less than one half of what it originally 
weighed, and capable of standing up under greater 
strain, methods were devised whereby low grade steel 

234 



Hardening bicycle parts. 

could be hardened in a manner that insured its standing 
as well as if the article was made of the more costly 
tool steel. 

Crank axles were made of 40-point carbon open 
hearth steel, which was given sufficient stiffness by 
heating red-hot and plunging in hot oil. When the 
percentage of carbon was lower than that mentioned — 
40-point — it was sometimes found necessary to pack 
the axles in a box with granulated wood charcoal, sub- 
jecting them to a red heat for a period of from 2 to 6 
hours; they were then dipped in hot oil. If the per- 
centage of carbon was too low to insure hardening by 
this process, they were packed in a box with equal 
parts of charred leather and charcoal, run for a suffi- 
cient length of time, and quenched as described. 

It was found necessary to make handle bar binders 
very light. When made of tool steel, hardened and 
tempered, the cost was too great, and if made of ordi- 
nary machine steel, case hardened, they were elastic, 
but stretched when strain was put on them. By using 
a 30-point carbon steel packing in charcoal, and running 
1 hour after they were red-hot, then plunged in hot oil, 
tney gave as good satisfaction as though made of tool 
steel, while the cost of machining was not one-quarter 
as much. 

Hardening bevel gears for bevel gear chainless 
bicycles caused a great many anxious moments in shops 
where it was attempted. One prominent manufactur- 
ing concern lost at one time 75 per cent, of all gears 
hardened, according to their own statement. 

At the time mentioned the writer was connected 
with a concern manufacturing a high-grade chainless 
wheel. The gears were of the design represented in 

^35 



Case hardening bicycle parts. 

Fig- 135. They were made of 40-point carbon open 
hearth steel, which was extremely low in phosphorus. 
When hardened, they were packed in a hardening box 




Crank Axle Gear 



Pinion Gear 



Figure 135. 

Bicycle parts case 

hardened. 




with a mixture of granulated charred leather and char- 
coal, run at a red heat for a sufficient length of time to 
make the teeth hard enough to resist wear, yet not 
brittle enough to break when in action. This was the 
reason it was necessary to use a steel of a very low 
percentage of phosphorus. 

The crank axle gear, as shown above, was run 
ify hours after it was red-hot, then dipped in a bath of 
raw linseed oil at a temperature of ioo degrees Fahr. 

2^6 



Different case hardening results. 

The surfaces of the teeth were extremely hard ; the gear, 
being made light to reduce weight, necessarily had to 
be very stiff, yet tough. They gave the best of satis- 
faction. Another concern in the same line of business 
packed their gears in granulated raw bone, with the re- 
sult they were so brittle it was found impossible to use 
them. Still another packed their gears in raw bone, run 
them for one hour after they were red-hot, then allowed 
them to cool, reheated and hardened. The gears were so 
brittle the teeth would break when the surfaces were 
not sufficiently hard to resist wear. Both concerns 
adopted the method in use in our factory and had 
excellent results. 

While bone is an excellent hardening agent, it is 
not good practice to pack steel in it for case hardening, 
if brittleness is objectionable in the hardened product, 
because, as previously stated, raw bone contains phos- 
phorus, and phosphorus when present in steel, es- 
pecially in combination with carbon, causes the steel to 
be brittle. 

The pinion gear, shown in Fig. 135 on preceding 
page, was hardened in the same manner as the one 
mentioned, with the exception of the temperature of 
the bath, which was about 60 degrees. When hard- 
ening the small gears, it was found possible to wire 
several on the same wire, being careful to have suffi- 
cient space between them to insure good results. 
The advantage of this method of wiring was that a 
great amount of time was saved when dipping in the 
bath. While it was necessary to dip the large gear 
in the bath in a vertical position, working it up and 
down, the small gears were dipped in any position, as 
their shape prevented their springing. 

237 



Case hardening small screws. 

The gears, shown in Fig. 136, were used on the rear 
end of the gear shaft and rear hub, and were hardened 
in the same manner as the crank axle gear. 





The Derry Collard Co. 



Hub Gear 



Gear Shaft Rear End Gear 

Figure 136. Bicycle parts 
case hardened. 

While the critic might 
claim that some of the ex- 
amples given do not prop- 
erly belong under the head 
of case hardening, it has 
seemed advisable to group 
them under this head, be- 
cause they are, as a rule, so classified in most shops. 

It is generally advisable when case hardening 
screws made of Bessemer steel wire, to pack in expended 
bone. In this way the extreme brittleness incident to 
the use of raw bone is done away with in a great 
measure. The writer has seen batches of small screws 
(1% inch and under) made of Bessemer screw stock, 
which was packed in raw bone and hardened, so brittle 
that they would break from the necessary power ap- 
plied to a screw-driver to screw them into the hole. At 
the same time, when annealed, they filed easier, and 
were apparently softer than a piece of the rod they were 
made from. They had been heated to the different 
temper colors in order to toughen them, but it did no 

* 3 8 



Charred leather toughens. 



good. They were so brittle, even when annealed, that 

they were useless. 

Yet screws made from stock out of the same batch, 

packed in expended bone and run for the same length 

of time, were apparently all right. Had charred leather 

been used, it 
would have made 
them tougher, but 
the expended bone 
made them tough 
enough for all 
practical purposes. 
As it is much 
cheaper and more 
readily obtained, 
it is generally used 
for work of this 
class. 

When case hard- 
ening small pieces, 
which do not re- 
quire a deeply 
hardened portion, 
but which must be 
uniform, as bicycle 
chain links, it is 
advisable to use 
boxes made espe- 
cially for them, in 
box may become 
The writer has in 




Fig. 



The Dairy Colkird Co 

137. Another form of box 
for case hardening. 



order that all the pieces in the 

heated at about the same time. 

mind a certain stock used for making bicycle chain 

block links, which was packed in a box of the de- 



239 



How to pack snap gauges. 

scription shown in Fig. 137, using as packing 
mixture equal parts animal charcoal, wood char- 
coal and charred leather. The work was run 45 
minutes after it became red-hot, then dumped in cold 
water, and gave excellent results. The links tested 
showed up well, and the chains gave the best of satis- 
faction when on the wheels. A different stock was 
procured, and it was found by experiment that links 
made from the new stock could be run only 25 minutes 
after they became red-hot. If run the same length of 
time as those made of the first stock used, they would 
break very easily, but when run only 25 minutes gave 
very good satisfaction. 

In many shops it is customary to make snap gauges 
of machine steel. They are much easier made, the 
cost of material is less, and, if hardened properly, they 
will wear well. It is best, in cases of this kind, to use 
open hearth steel rather than Bessemer, as the latter 
runs more uneven. The best results will be obtained 
if we use as packing material granulated leather instead 
of bone.* When packing, mix with an equal amount 
of granulated charcoal, run five or six hours, if the 
gauge is % inch thick or more. Run at a very low 
heat, and dip in the oil bath. It will be found to be 
very hard, and probably straight. If hardening small 
pieces, it is advisable to use smaller boxes than when 
large pieces are being treated, as it takes some time to 
heat a large box through. Pieces near the walls of the 
box will become hot quicker than those in the center, 
and consequently will be hardened deeper. 

Many pieces of work are made of tool steel when 
machine steel would answer the purpose as well, or 
better, were it not for the coarseness of the grain when 

240 



Machine steel used as tool steel. 

the piece is case hardened. The fine grain may be 
necessary to resist pressure and wear on some small 
part of the surface, or possibly it is to be subjected to 
the action of blows, and the grain being coarse, the 
surface has no backing and is soon crushed in. The 
causes of the open grain are : first, that it is the natural 
condition of the stock ; second, the pores are open when 
heated, and the steel is absorbing carbon. The higher 
the heat to which the pieces are subjected, the coarser 
the grain. 

It is possible to heat machine steel in such a man- 
ner as to produce a fine grain — in fact, as fine as that 
of the nicest tool steel. While the writer would not be 
understood as advocating the use of machinery steel in 
the making of nice tools, as so good an article cannot 
be produced as if made of tool steel, yet for certain 
purposes cutting tools are made of a good grade of open 
hearth steel, case hardened very deep, with fine compact 
grain, which gives excellent results. This is particu- 
larly the case where the cutting part is stubby and 
strong. Cams made of low grade steel, and hardened 
by this method, will resist wear as well as though made 
of tool steel and hardened, and they are not as liable to 
flake off or break. Punch press dies that are to be used 
for light work, cutting soft metals where there are no 
projections, will do very satisfactory work. Gauges, 
whether they be snap, plug, ring or receiving, are 
hardened with much less liability of their going out of 
shape, are easier to make, and will wear as long as 
though made of tool steel. Then, too, the necessity of 
allowing them to "age" after hardening, before grind- 
ing to size, as is the case when gauges are made of tool 
steel for accurate work, is done away with. 

241 



What is needed in case hardening. 

Many bicycle parts, formerly made of a good grade 
of tool steel, are now made of machine steel, and the 
best of results are obtained. Such is not apt to be the 
case if they are simply case hardened by the ordinary 
method, as the grain is too coarse to resist the peculiar 
action of the balls, particularly on the cones and ball 
seats. Spindles of machines, where there is considera- 
ble tendency to wear, also a pounding or twisting mo- 
tion to resist, where tool steel would be liable to break 
and ordinary case hardening would yield to such an 
extent as to make the bearings out of round, can be 
treated very successfully by this method. 

All that is needed is a good hardening furnace, 
large enough to receive as many boxes as we may need, 
a plentiful supply of boxes, some granulated raw bone, 
a good supply of charcoal and a small amount of hydro- 
carbonated bone, and some charred leather for our 
nicest work. We should also have a suitable supply of 
water in a large tank, and a smaller tank arranged so 
that we can heat it to any desired temperature, and a 
bath containing raw linseed oil. The work should be 
packed in the hardening boxes as for ordinary case 
hardening, run about the same length of time, and left 
in the oven to cool the same as for annealing. 

When cool, the articles may be heated in the 
open fire, muffle furnace or in the lead crucible, and 
hardened the same as tool steel ; or, if the articles are 
small, and there are many of them, they can be re- 
packed in the hardening box with charcoal. But do 
not use any carbonizing substance, as that would have 
a tendency to open the grain, and the object of the 
second heat is to close the grain. • The lower the hard- 
ening heat, the more compact the grain will be, as is 

242 



Case hardening metal cutting tools. 

the case with tool steel. This method not only gives a 
close grain, but a very strong, tough surface, and, the 
center being soft, the piece is very strong. 

When hardening tools whose office it is to cut 
metals, it is always best to use a packing mixture of 
equal parts of charred leather and charcoal. The 
kernels should be fine and of about the same size, if 
possible, for if the kernels of the leather were large, 
and those of the charcoal were small, the tendency 
would be for the finer to sift to the bottom of the box. 
Leather gives a stronger, tougher effect than bone, it 
being practically free from phosphorus, while bone 
contains a large percentage. The presence of phos- 
phorus in steel makes it brittle, especially when com- 
bined with carbon. Yet for most purposes where there 
are no cutting edges bone works very satisfactorily in 
connection with machinery steel, and is much cheaper 
than leather. When using either bone or leather, mix 
with an equal quantity (by measure) of granulated 
charcoal. Being well mixed, the particles of charcoal 
keep the kernels of bone or leather from adhering to 
each other and forming a solid mass when heated. 
Then again, the charcoal has a tendency to convey the 
heat through the box much more quickly than would 
be the case were it not used. 

If small pieces are to be hardened that do not need 
carbonizing more than -gV of an inch deep, it is best to 
use No. 2 granulated raw bone. If the pieces require 
a very deep hardened section, it will need a coarser 
grade, as they must run longer in the fire. When 
hardening bicycle cones and similar articles, where it is 
necessary to carbonize quite deeply, it is best to pack 
with No. 3 bone and charcoal, equal parts, or better 

*43 



To case harden thin pieces. 

yet, with two parts raw bone, two parts charcoal and 
one part bone black or animal charcoal. Pack in the 
hardening box, as previously described, run in the fur- 
nace 10 hours after the box is heated through, using 
the test wires to determine the beginning of the heat. 
After the work is cold, it can be reheated as described 
and hardened. It is advisable to occasionally break a 
piece of work and examine the grain, noticing how 
deep the hardening has penetrated. If not deep enough, 




The Deny Collard Co. 
Figure 138. Piece to be hardened, leaving the center soft. 

repack in the boxes with fresh material, and run again ; 
but if directions given are followed closely, results will 
in all probability be found satisfactory. The grain, as 
far in as the carbon has penetrated, should be as fine 
as that of hardened tool steel. 

In hardening thin pieces, where it is necessary to 
resist wear or blows, it is advisable to use leather as a 
packing material, hardening in a bath of raw linseed 
oil. The pieces will be found extremely tough and 
hard. It is sometimes desirable to harden the ends of 
a piece of work, leaving the center soft. Take, for in- 
stance, the piece shown in Fig. 138. The surface of the 



244 



Case hardening thin pieces. 

ends marked a needs hardening, while the portions 
marked b should be soft. Pack the ends inside and out 
with hydrocarbonated bone and charcoal, having pre- 
viously filled the center with expended bone. Cover 
the outside of the center with expended bone, run in 
the oven 7 or 8 hours after the box is 
heated through. Allow the work to 
cool as described, remove the pieces 
from the box, heat the ends separately 
in the lead cruci- 
ble, dip in a bath Fi e ure «39- 
of lukewarm How to di P thin 
water, dipping pieces - 
with the heated 
end a up, as 
shown in Fig. 139. 
Otherwise the 
steam generated 
from contact of 
the hot steel with 
water would pre- 
vent the water 
from entering 
the end where it 
dipped with the 
heated end down. 
If the water can- 
not enter the 
work and get at the portions necessary to be hard, 
they certainly will not harden. If the piece is dipped 
with the heated end as described, the water readily 
enters. The ends will be found extremely hard, and 
the grain will be very compact. Not only is this so, 




The Derry Collard Co. 



245 



Case hardening bicycle axles. 

but the piece will be much less liable to crack than 
if the extreme ends were dipped first and hardened, as 
would be the case with the heated end down. 





The Derry Collard Co. 



Figure 140. Bicycle axle. 



Another method employed when hardening the 
ends of a piece of work and leaving the center soft, can 
be illustrated by the bicycle axle shown in Fig. 140. 
The ends are machined to shape, the center being left 
large, as represented at a. The axle is packed in the 
hardening box and charged with carbon, as described. 
The center is then cut below the depth of charging 
shown at b. The piece is ready for hardening. This 
can be accomplished by heating in an open fire, muffle 
furnace or lead crucible, and dipping in the bath. 

When it is necessary to harden the center of a 
piece and leave the ends soft, it can easily be accom- 
plished. If the ends are to be smaller than the center, 

246 



How to harden bicycle chain studs. 

the pieces may be packed in the hardening box with 
raw bone and charcoal. Run for a sufficient length of 
time to carbonize to the desired depth of hardening. 
Allow the pieces to cool off. When cool, machine the 
ends, as shown by lower cut in Fig. 141, the upper cut 



The Derry Collard Co. 

Figure 141. Method of treatment for chain studs. 

representing the piece of work before charging with 
carbon; the lower, after machining the carbonized 
portions at the ends. It may now be heated red-hot 
and dipped in the hardening bath in the usual man- 
ner. The center will be found hard. 

A method employed in making bicycle chain studs 
that are hard in the center at the point of contact with 
the block link and soft on the ends, in order that they 
may be readily riveted in the side links, consists in 
taking screw wire or special stud wire of the desired 
size, packing it in long boxes with raw bone and char- 
coal and running 3 or 4 hours after it is red-hot. Then 
allow it to cool off. The stock is now placed in the 
screw machine and cut to shape — that is, the ends are 
cut down to proper size. The center, being of the 
proper size, is not machined. The studs may be heated 

247 



An interesting experiment. 

in a tube in any form of fire and dumped in a bath of 
water or brine. The center will be hard enough to re- 
sist wear, while the ends will be soft, the carbonized 
portion having - been removed. 

An interesting experiment can be tried, which in 
itself is of no particular value, except that it acquaints 





b 




b 




b 




a 


a 


a 


a 











The Deny Collard.Co. 

Figure 142. An interesting experiment. 

one with the manner in which carbon is absorbed by 
steel. Take a piece of open hearth machinery steel, 
turn it in the lathe to the shape shown in Fig. 142, neck- 
ing in every half inch to the depth of }i inch, leaving 
the intervening spaces % inch long. Pack the piece 
in the hardening box with raw bone and charcoal. 
Run five or six hours after the box is heated through. 
When cold, turn the shoulders marked b to the size of 
a, leaving a the same size as before charging. Heat to 
a low red and dip in the bath. The portions marked 
a will be found hard, while the balance of the piece 
will be soft. 

When pieces are to be case hardened, and it is con- 
sidered desirable to leave a certain portion soft, it is 
accomplished many times by making tongs of the 
proper form to effectually prevent the contents of the 
hardening bath coming in contact with the portion men- 

248 



Case hardening to leave soft places. 



tioned Suppose, for example, a piece of the design 
shown in Fig. 143 is to be case hardened, and itisde- 



-P R T I O N-DE S IR-ED-SO FT- 



The Derry Collard Co. 

Figure 143. Piece with portion desired soft 



sired to leave the central 
pair of tongs to grasp th 
It will be seen that 
tioned is effect- 
the tongs. The 
in the bath, and 
until the red has 
it may be dropped 
tank and left until 
desirable to leave a 



portion marked soft. Make a 
e piece, as shown in Fig. 144. 
the portion m e n - 
ually protected by 
piece may be dipped 
worked around well 
disappeared, when 
to the bottom of the 
cold. When it is 
portion of an article 



The Deny Collard Co. 

Figure 144. Tongs for handling piece shown above. 

soft, as shown in Fig. 145, it is sometimes accomplish- 
ed by covering the portion to be soft with fire-clay, as 
shown in lower view. The fire-clay may be held in 
place by means of iron binding wire ; sometimes the 
fire-clay is held in place by means of plasterers' hair, 



249 



The use of fire-clay for soft places. 

which is worked into the mass when it is mixed with 
water. The fire-clay prevents the carbon coming in 
contact with the stock where it is desired soft. 




The Derry Collard Co, 

Figure 145. The use of fire-clay for soft spots. 



A method employed in some shops consists in 
wrapping a piece of sheet iron around the article over 
the portion de- 
sired soft, as 
shown in Fig. 146. 
The sheet metal is 
held in place by 
means of iron 
binding wire, as 
shown. 



The Derry Collard Co. 



Figure 146. Using sheet iron to 
prevent hardening. 



A very common method, which is costly when 
many pieces are to be treated, consists in forcing a 



250 



The use of a collar in case hardening. 

collar on to the piece over the portion desired soft, as 
shown in Fig. 147. The collar is removed alter the 
article is hardened. 



Piece to be hardened 




Collar 



The Derry ColJard Co. 



Collar in position 
Figure 147. A collar for keeping portions soft. 



When machine nuts are to be case hardened, and 
for any reason it is desirable to have the interior 
threaded portion soft, it is accomplished by screwing 
a threaded piece of stock in the hole before the nuts 
are packed in the hardening box. 

As carbon can not penetrate a nickeled surface, 
articles are sometimes nickel-plated at portions desired 
soft; this, however, is, generally speaking, a costly 
method of accomplishing the desired result. 

It is sometimes considered necessary to harden the 



251 



How to produce toughness. 

surfaces of pieces quite hard and leave the balance of 
the stock stiffer than would be the case where ordinary 
machinery steel is used. In such cases many times an 
open hearth steel is selected, which contains suf- 
ficient carbon, so that it will become very stiff when 
quenched in oil. The writer has in mind a gun frame 
which, on account of the usage to which it was to be 
put, must have a hard surface, while the frame itself 
must be very stiff. They were packed in a mixture of 
charred leather and charcoal, placed in the furnace and 
run for a period of i^ hours after they were red-hot. 
They were then quenched in a bath of sperm oil. The 
stock used was 30-point carbon open hearth steel. Were 
the articles heavier or a greater degree of stiffness de- 
sirable, a steel could be procured having a greater per- 
centage of carbon. 

When toughness or strength is wanted in the case 
hardened product, a steel having much phosphorus 
should not be used ; in fact, the percentage of phosphorus 
should be the lowest possible, as steel containing phos- 
phorus, in connection with carbon, is extremely brittle. 
For this reason, articles which must be extremely tough 
should not be packed in raw bone, as this contains a 
very high percentage of phosphorus. 

At times a job will be brought around to be case 
hardened, and one particular part will be wanted quite 
hard, while the balance of the piece will not require 
hardening very hard or deep. In such cases, if the por- 
tion mentioned be a depression, it may be placed upper- 
most in the hardening box, and some prussiate of 
potash or a small amount of cyanide of potash placed 
at this point, the piece being packed in granulated raw 
bone or leather, and run in the furnace a short time. 

252 



Furnaces for case hardening. 

The article may be quenched in the usual manner. The 
portion where the potash was placed will be extra hard. 




The Deny Collai-d Co 



Figure 148. Gas furnace for case hardening. 



The furnace used in case hardening should receive 
more consideration than is many times the case; an 
even heat that can be maintained for a considerable 
length of time is essential if best results are desired. 

A very satisfactory form of furnace is represented 
in Fig. 148; it burns illuminating gas as fuel. 

When it is considered desirable to use hard coal as 

»53 



A "home-made" case hardening furnace. 

fuel, the furnace made by the Brown & Sharpe Co., of 
Providence, R. I., gives excellent results. 

When it is considered advisable to construct on the 



Oi 



Figure 149. "Home-made" furnace 
for case hardening. 




ur <i Co. 



premises a furnace burning charcoal or coke, the form 
shown in Fig. 149 will be found very satisfactory. 

However, the form and size of furnace depend in a 
great measure on the character and amount of work to 
be hardened. 

Baths for Case Hardening. 

The bath that is to be used for cooling work being 
case hardened must be suitable to the work being 



254 



Various styles of case hardening baths. 

hardened. Where work is case hardened in large 
quantities, it is customary in most shops to harden in 
iron boxes. When the work is in the proper condition, 
the box is inverted over a tank of water or some fluid, 
and the contents dumped into the bath. If the pieces 
of work are large or bulky, and the tank is shallow, 
they reach the bottom while red-hot, and, as a con- 
sequence, the side of the piece that lays on the bottom 
will be soft. In order to overcome this trouble, the 
tank must be made deep enough so that the pieces will 
be sufficiently chilled before reaching the bottom. If 
it is not considered advisable to have an extremely deep 
tank and the pieces are large, various ways are taken 
to insure their hardening. 

One method which the writer has used with excel- 
lent results is to have a series of rows of wire rods 
reaching across the tank, no two consecutive rows being 
in the same vertical plane, as mentioned in the previous 
section. The work as it descends into the bath strikes 
these wires, which turns them over and over, bringing 
all portions in contact with the contents of the bath. 
These wires also separate the pieces from each other 
and from any packing material which may have a 
tendency to stick to them. The wires also retard the 
progress of the articles, giving them more time to cool 
before reaching the bottom of the bath. 

In order to insure good results, it is necessary to 
have a jet of water coming up from the bottom of the 
tank. An outlet is provided near the top for an over- 
flow. The overflow pipe, of course, should be larger 
than the inlet pipe, and should be located far enough 
below the top edge of the tank, so that the contents will 
not overflow when a box of work is dumped into it. 

*55 



Bath with catch pan. 



In order to get the hardened pieces out of the bath 
easily, it is necessary to provide a catch pan, as shown 
in Fig. 150. The bottom of this pan should be made of 
strong wire netting or a piece of perforated sheet metal, 
preferably the former. The holes in the pan allow the 
packing material to fall through to the bottom of the 

tank, and also 
allow the water 
from the supply 
pipe to circulate 
freely around the 
work and to the 
top of the bath. 
This catch pan 
should be provided 
with strong wire 
handles, as shown, 
in order that it may 
be readily raised. 

I was at one time 
requested to call at 
a shop where they 
were having very 
unsatisfactory re- 
sults with their 
case hardening. An examination showed they were 
dumping their product into a barrel of water to harden. 
The box containing the work was inverted over this 
barrel, and the work and packing material went into 
the water in a lump. Some of the pieces that hap- 
pened to get out of this mess were cooled sufficiently 
to harden somewhat, but the majority of the pieces were 
soft, or else they were hard on one side and soft on the 

256 




The Derry Col lard Co. 



Figure 150. Case hardening bath with catch 
pan and steam pipe. 



How a temporary bath was arranged. 

other. An examination of the bottom of the barrel 
showed it to be considerably charred. In places the 
outline of the pieces was plainly visible. These pieces 
had reached the bottom red-hot, and had burned their 
way into the wood. It is needless to say that the side 
of the piece of work which was down did not harden. 

As those in charge of the work did not think it ad- 
visable, considering the limited amount which they had 
to case harden, to get a tank of the description shown 
in Fig. 150, we made a catch pan as described, blocked 
it up about 6 inches from the bottom of the barrel 
by means of bricks. We then bored a hole into the 
bottom of the barrel, screwed in a piece of pipe, and by 
this means were able to connect an ordinary garden 
hose, so as to get a jet of water coming up from the 
bottom. As the barrel was out of doors, we simply 
bored a two-inch hole about two inches from the top of 
the barrel for an overflow, and let the water run on 
the ground. When the work was ready to dump, we 
sifted it out of the box into the water gradually, rather 
than to dump it in a body. As socm as the box was 
emptied, we grasped the wire connected with the catch 
pan, and raised and lowered the pan in a violent man- 
ner, in order to separate any pieces that might have 
lodged together. The result was very satisfactory, and 
I think they are still using that barrel. 

Baths are made, when large quantities of work are 
hardened, with some means of keeping the work in 
motion after it reaches the bottom of the bath. This 
is sometimes done by mechanically raising and lower- 
ing the catch pan, and at the same time turning it 
around. Then again, it is done by means of several 
sweeps, which are attached to the lower end of a verti- 

257 



Baths with air pumps or perforated pipes. 



Supply Pipe 



o=^ 



The Derry Collard.Co. 



cal shaft, the shaft resting in a hearing in the center of 
the catch pan. These sweeps, or arms, revolving, keep 
the pieces in motion, turning them constantly, but un- 
less arranged 
properly, they 
have a tendency 
to gather the 
work in batches, 
thereby acting 
exactly opposite 
from what they 
are intended to 
do. Then again, 
they have a ten- 
dency to scratch 
the surface of the 
work, which is a 
serious objec- 
tion, if color 
work is wanted. 
When it is de- 
sirable to get nice colors on case hardened work, an 
air pump may be connected with the bath, as shown in 
Fig. 134, the water and air entering the bath together. 
While it is not advisable to let air come in contact with 
the pieces to be hardened for colors while passing from 
the box to the water, yet the presence of air in the 
water would have the effect of coloring the work nicely. 
When hardening long slender articles or those 
liable to give trouble if a bath of the ordinary descrip- 
tion is used, excellent results may be obtained by the 
use of a bath with perforated pipes extending up the 
sides of the tank, as shown in Fig. 151. 

z S 8 




Figure 151. Bath for cooling slender 
case hardened articles. 



Spring Tempering 



W 



When it is necessary to give articles made of steel a 
sufficient degree of toughness, in order that when bent 
they will return to their original shape, it is accom- 
plished by a method known as spring tempering. 

The piece is first hardened, then the brittleness is 
reduced by tempering until the article, when sprung, 
will return to its original shape. 

Generally speaking, it is not advisable to quench 
pieces that are to be spring tempered in cold water, as 
it would not be possible to reduce the brittleness suffi- 
ciently to allow the piece to spring the desired amount 
without drawing the temper so much that the piece 
would set. Steel heated red-hot and plunged in oil is 
much tougher than if plunged in water ; and as tough- 
ness is the desired quality in springs, it is advisable to 
harden in oil whenever this will give the required result. 

For many purposes a grade of steel made especially 
for springs gives better results than tool steel ; for in- 
stance, bicycle cranks made of a 40-point carbon open 
hearth steel will temper in a manner that allows them 
to stand more strain than if made of the finest tool 
steel, and the stock does not cost more than one-quarter 
the price of tool steel. 

When springs are to be made for a certain purpose^ 
259 



Plow to harden clock springs. 

it is generally safer to state the requirements of the 
spring to some . reliable steel maker, allowing him to 
furnish the stock best suited for the purpose, than to 
attempt to specify the exact quality wanted — unless, of 
course, the operator or manufacturer has, either by ex- 
perience or by study, acquired the knowledge necessary 
to qualify him to judge as to the quality needed. 

As previously stated, the hotter a piece of steel is 
heated for hardening the more open the grain becomes ; 
and as hardened steel is strongest when hardened at 
the refining heat, it is always advisable to heat no hot- 
ter than is necessary to accomplish the desired result. 
But as springs are generally made of a steel lower in 
carbon than ordinary tool steel, and as low carbon 
steel requires a higher heat to harden than is the case 
when tool steel is used, it is necessary to experiment 
when a new brand of steel is procured, in order to as- 
certain the proper temperature in order to produce the 
best results. 

When steel is heated to the proper degree, it may be 
plunged in a bath of oil or tallow and hardened, the 
character of the bath depending on the size of the piece 
to be hardened and the nature of the stock used. For 
ordinary purposes a bath of sperm oil answers nicely. 
In some cases tallow will be found to answer the pur- 
pose better. It is necessary sometimes to add certain 
ingredients to the bath in order to get the required de- 
gree of hardness. 

The following is used by a concern when hardening 
clock springs: To a barrel of oil add 10 quarts of 
resin and 13 quarts of tallow. If the springs are too 
hard, more tallow is added. If, however, the fracture 
indicates granulation of the steel rather than excessive 

260 



Mixture for hardening springs. 

hardness, a piece of yellow bees'- wax of about twice 
the size of a man's fist is added to the above. 

The following mixture has been used by the writer 
with success in hardening springs which, on account of 
the thickness of the stock or a low percentage of carbon, 
would not harden in sperm oil : 

Spermaceti oil 48 parts. 

Neat's foot oil 46 " 

Rendered beef suet 5 " 

Resin 1 " 

The proportion of the different ingredients may be 
changed to meet the requirements of the particular 
job. Resin is added to the oil to strike the scale. As 
the scale or oxidized surface of the steel, when subjected 
to heat, is liable to raise in the form of blisters, and as 
these are filled with gas, the contents of the bath can 
not act readily on the steel. A small proportion of 
spirits of turpentine is sometimes added to the oil for 
the same purpose, but as it is extremely inflammable, 
it is somewhat dangerous to use unless great care is 
observed. The presence of resin in a hardening bath 
has a tendency to crystallize the steel, and on this ac- 
count is sometimes objectionable. 

A very good method, when neither resin nor turpen- 
tine are used to strike the scale, consists in having a 
dish of soft soap ; or, if that can not be procured, dis- 
solve some potash in water, dipping the steel into this 
before heating. It has the effect of preventing oxida- 
tion of the surfaces, and helps to strike any scale that 
may have been on the stock previous to hardening. 

When small springs are to be hardened, which, on 
account of their size, cool quickly, they can. if there 
are many of them, be placed in tubes and heated in a 

261 



Furnace for heating springs. 

furnace of the description shown in Fig. 152. When 
the pieces are heated to the proper temperature, a tube 
is removed and inverted over a bath. The contents 
should go into the bath in a manner that insures uni- 
form results, that is, the pieces should be scattered in 
the bath. If the tube was held in the position shown 



Figure 152. Furnace with removable tubes for 
heating springs. 



OOOO 

OOO 
OOOO 




The Derry CollardCo. 



at a, in Fig. 153, the pieces would go into the bath in a 
lump; but if it were held as shown at b, the pieces 
would become scattered, thus insuring good results. 

When springs larger than those previously con- 
sidered are to be hardened, an oven having some means 
of heating the articles in a manner that keeps them 
from coming in contact with the products of combus- 
tion should be used. Any form of a muffle having 



262 



An oil bath for spring hardening. 



Figure 153. 

How tubes shown ii 

Figure 152 should 

be emptied. 



sufficient capacity will do, or the pieces may be placed 
in a hardening box, having ^ inch powdered charcoal 
in the bottom, and a cover placed on the box — which 
need not be sealed. The box may then be placed in a 
furnace and subjected to heat. The cover may be 
raised from time to time and the contents of the box 
noted. This makes an excellent way of heating large 
coil springs and similar articles. 

If the oven is sufficiently large, several boxes may 
be heated at a a 

time. When a 
spring shows the 
proper tempera- 
ture, which 
should be uni- 
form through- 
out, it may be re- 
moved, placed on 
a bent wire and 
immersed in a 
bath of sperm oil, 
having a jet of 
oil coming up 
from the bottom, 
as shown in Fig. 
154, A repre- 
senting the outer 
tank containing 
water, B the bath 
of oil, C the pump used in drawing the heated oil from 
the bath through the pipe D ; it is then forced through 
the coil of pipe in the water and back into the bath 
through the inlet E. F is the catch pan. The jet of 

263 




The Deny. Collard C*. 



Oil bath for spring tempering. 

oil is forced toward the top of the tank, as shown at G. 
The spring should be worked up and down in the 
bath until all trace of red has disappeared, when it 
may be lowered to the bottom of the tank and left 
until the temperature has been reduced to that of 
the contents of the tank, or until a convenient time 
comes for their removal. 

As previously explained, it is not advisable to re- 
move articles being quenched from the bath until they 




l=fc 



The Derry Collard Co. 

Figure 1 54. Oil bath for spring tempering. 

are of a uniform temperature throughout. While this 
procedure might not make as much difference with a 
piece of work hardened in oil as one hardened in water, 
yet it is not a good plan to remove articles from the bath 
until they are reduced throughout to the temperature of 
the bath. 

In order that the contents of the bath may be kept a 
uniform temperature, the pump shown in accompany- 
ing cut may be connected with the tank, as represented, 
the oil to be taken from near the top and pumped 



204 



How to heat heavy springs. 

through the coils of pipe in the outer tank, which 
should be supplied with running water. 

When steel contains carbon of too low a percen- 
tage to harden properly in oil or any of the mixtures 
mentioned, the writer has used a bath of water at, or 
nearly at, the boiling point (212 ) with very gratifying 
results. It may be found necessary with certain steels 
to reduce the temperature of the water somewhat. 

Various methods are employed when drawing the 
temper. The one more commonly used than any other 
is to heat the spring until the oil adhering to the sur- 
face catches fire and continues to burn, when the piece 
is removed from the fire, burning until all the oil has 
been consumed. If this method is used, it will be 
found necessary to provide some means whereby a 
uniform heat may be obtained, or one part of the spring 
will be found to be too soft by the time the balance is 
rightly tempered. 

If the spring is of heavy stock, it is necessary to burn 
the oil off three and sometimes more times, in order to 
bring it to the proper degree of elasticity. The process 
of drawing the temper by heating the spring until the 
oil catches fire from the heat contained in the steel is 
familiarly known as "flashing." Hardeners say that 
it is necessary to flash oil off this spring three times, 
or it is necessary to flash tallow off this spring twice, 
some using the oil the piece was quenched in, while 
others prefer some other kind of oil or tallow. 

Springs hardened in boiling water may be coated 
with oil or tallow and the temper drawn as described, 
if it be found necessary. It is not policy to use a fire 
having a forced draft or blast when drawing articles 
to a spring temper. An open fire burning wood or 

265 



The thermometer in spring tempering. 

charcoal gives excellent results. A gas flame having 
no air blast also works very satisfactorily. 

Springs of unequal sizes on the various portions re- 
quire a very skillful operator, in order to get uniform 
results, if the above method is used. The thinner 
portions, heating faster than the heavier parts, be- 
come too soft before the other parts are soft enough. 
Consequently, it is advisable to temper these by a dif- 
ferent method. The spring may be placed in a per- 
forated pail, which in turn is set into a kettle of oil or 
tallow. This kettle is placed where a sufficient amount 
of heat may be obtained to draw the temper to the 
proper degree. 

The amount of heat given is gauged by a ther- 
mometer, and varies according to the nature of the 
steel and the character of the spring. It ranges from 
560 to 63 o°. The exact amount of heat necessary must 
be ascertained by experiment. This method furnishes 
a very reliable way of tempering all kinds of springs. 
The kettle should be so arranged that a cover may 
easily be placed on it in case the oil catches fire, as 
otherwise the operator, or the building, might be burned, 
or the work in the oil spoiled, or the thermometer 
cracked. The cover should be made high enough to 
take in the thermometer. 

The cover should be provided with a long 
handle, in order that the operator may not be burned 
when putting it on the kettle. If it is not considered 
necessary to provide the cover mentioned, a piece of 
heavy sacking should be kept conveniently near for 
use. If this is placed over the top of the kettle, it will 
generally extinguish the flames. 

The thermometer should not be taken from the hot 

266 



Heating watch springs. 

oil and placed where any current of air can strike it, or 
the glass will crack. It is advisable to leave it in the 
oil, letting - it cool down with it. If the furnace 
where the oil is being heated is located where any cur- 
rent of air will strike the thermometer, it must be pro- 
tected in some manner, or it will crack. 

If it is considered advisable to remove the pail of 
work from the oil before the pieces are cool, it may be 
done, and the pieces dumped into a wooden box, cover- 
ing the opening, so that the air will not strike the 
pieces. The pail may now be filled with fresh pieces 
requiring tempering. The pail of work should be 
placed in the kettle of oil. The kettle should not be 
placed in the fire again until the pieces of work have 
absorbed considerable of the heat that was in the oil, 
when the kettle may be placed in the fire and the 
operation repeated. 

When work is hardened in large quantities, it is 
generally considered advisable to devise methods that 
allow of handling the work cheaply, at the same time 
keeping the quality up to the standard. Watch springs 
are sometimes heated in a crucible containing melted 
cyanide of potassium or salt and cyanide of potas- 
sium heated to the proper degree. The springs 
are immersed in the mixture until uniformly heated, 
then quenched. It is stated, however, that this 
mixture will not do when heating the hair springs, 
as it causes the nature of the steel to change 
slightly. These springs are heated for hardening in a 
crucible of melted glass. 

When a make of steel is found that gives satisfac- 
tory results when made into springs and tempered, it is 
folly to exchange it for another make, unless convinced 

267 



The "second blue." 

that the other is better. A saving of a few cents, or 
even dollars, on an order of steel is quite often very 
costly economy, as many times springs do not give out 
until in actual use, and in that case they are often- 
times many miles from the factory where they were 
made. 

When large numbers of springs that must receive 
severe usage are made, it is advisable to give them a 
test — at least, test an occasional spring. Give them a 
test somewhat more severe than they will be liable to 
get in actual use. By so doing it is possible to detect 
an improper method of hardening or tempering before 
the whole batch is done. 



"Second Blue. 



>9 



When all springs were made of tool steel and 
hardened, and the temper drawn one at a time, it was 
customary with some hardeners to draw the temper to 
what is known as the "second blue." After harden- 
ing, the springs were polished, then placed in a pan of 
sand and held over the fire until the temper colors 
commenced to show, the pan in the meantime being 
shaken to keep the sand and springs in motion and 
insure uniform heating. The tempers will show in 
order as set forth in the color table given under 
Drawing the Temper. After the^ colors had all 
appeared, the surface of the steel assumes a grayish 
appearance. When heated a trifle above this, it as- 
sumes a blue color again, which is known as the 
"second blue." When this color appears, the spring 
should be dropped in a tank of hot oil, leaving it to 
cool oif with the oil. 

268 



Colors for springs — how obtained. 

Another method sometimes used when drawing the 
temper of heavy springs made from high carbon steel 
consists in heating the article until sawdust dropped 
on it catches fire, or a fine shaving left from a hard- 
wood stick, such as a hammer handle, being drawn 
across a corner of it, catches fire at the proper temper- 
ing heat. 

Mechanics are sometimes surprised when they ob- 
serve a spring in some conspicuous place which is drawn 
to a straw color, a brown or a light blue. It does not 
seem possible to them that a spring drawn to the tem- 
per represented by the color visible should be able to 
stand up to the work. The temper color shown is 
simply for appearance. The articles are first hardened 
and tempered to give them the necessary elasticity. 
This is ordinarily done by heating in a kettle of oil, 
gauging the heat with a thermometer. After heating 
to the proper temperature and cooling, they are 
polished. Any desired color can be given by placing 
the articles in a pan of sand and shaking over a fire 
until the desired color shows, when they may be 
dumped in warm oil to prevent running. This second 
operation does not affect the hardness or elasticity, 
provided they were not heated as hot as when the 
temper was drawn. 

Many times it is impossible to harden and temper a 
spring in a manner that gives satisfactory results, be- 
cause the spring was bent to shape when cold. Now, 
it is possible to bend most steel somewhat when cold, 
and yet have it take a good spring temper ; but it is 
impossible to bend it beyond a certain amount, which 
varies with the steel. 

The writer has seen large safety valve coil springs 
269 




Caution about annealing sheet steel. 

rendered unfit for use by coiling when cold. If a 
piece of the same steel was heated red-hot and coiled, 
excellent results were obtained. 

Many times it is necessary to anneal steel one or 
more times between operations in order to obtain good 
results. It was found 
necessary to anneal 
the spring shown in 
Fig. 155 after punch- 
ing the blank and 
before bending at all. 
The first operation of 
bending brought the 
spring nearly to 
shape ; it was then an- 
nealed, and the finish- 
ing operation taken. 
If it was bent to shape 
without annealing 
the second time, it 
would break in the 




Figure 155. 



The Derry Collard Co. 

A peculiar case. 



corners when in use, if not in the operations of bending. 
When annealing sheet steel, whether it be for springs 
or cutting tools, the utmost caution should be exercised. 
If the steel is allowed to stay in a red-hot condition for 
too great a length of time, the stock is rendered unfit 
for hardening. If heated red-hot and laid aside to cool 
slowly, much better results will follow than if it were 
packed in an annealing box with charcoal and kept red- 
hot for a considerable length of time. These long 
heats apparently have the effect of throwing the carbon 
out of its proper combination with the iron. It will 
harden, but can never be made elastic or strong. 



270 



Making Tools of Machine 
Steel. 



?=^9 




CO 



While it is considered advisable in most shops to 
make articles whose bearing surfaces must be hard, in 
order to resist frictional wear, of some form of machine 
steel, and give the surfaces sufficient hardness by case 
hardening, it is generally considered necessary to make 
cutting, forming and similar tools of tool steel. 

It is practical, however, to make cutting tools for 
certain classes of work of machine steel, and harden the 
cutting edges sufficiently to produce very satisfactory 
results. 

Steel is, as previously explained, a combination of 
iron and carbon. The grade of iron used in making 
tool steel is, however, vastly superior and much more 
expensive than that used in the manufacture of the or- 
dinary machine steel. Being much purer, it is much 
stronger when carbonized and hardened, and conse- 
quently can do many times the amount of work of tools 
made of the lower grades of steel, even when these are 
charged with the same percentage of carbon. It is also 
less liable to crack when hardened, as the impurities 
contained in the lower grades make it, when combined 
with carbon, very brittle when hardened. 

But notwithstanding the facts just presented, it is 
271 



How phosphorus affects steel. 

possible to make tools for cutting paper, wood, lead, 
brass and soft steel of a low grade of steel 5 and harden 
it by a process that gives results much more satisfac- 
tory than would be thought possible by one who had 
never tried it. This method recommends itself on ac- 
count of the comparatively low cost of the steel, and it 
can be worked to shape more cheaply than if tool steel 
were used. But it is usual, when the experiment is 
tried, to use any piece of low grade steel laying around 
the shop that will machine to shape in a satisfactory 
manner, not realizing that it is necessary, in order to 
get satisfactory results, to use steel adapted to the pur- 
pose. As phosphorus, when present in steel, and es- 
pecially when in combination with carbon, causes it 
to be extremely brittle when hardened, a grade should 
be selected that has the least possible percentage of this 
harmful impurity. 

If it is not necessary to have the hardened surface 
very deep, a steel having a low percentage of carbon 
may be used. If, however, the tool is to be subjected 
to great strains, it is advisable to use a steel containing 
sufficient carbon to cause the tool to harden enough to 
furnish the necessary stiffness or internal hardness. 
The extra amount of hardness necessary to insure the 
cutting portions standing up when in use, must be fur- 
nished by the process of hardening. 

The writer has seen reamers, counterbores, punch 
press blanking, forming and drawing dies, and many 
other forms of tools made of low grade steel, which, 
the parties using them claimed, gave the best of results. 

As before stated, when making tools which are not 
to be subjected to a very great amount of strain, or 
which will not be called upon to resist a great amount 

272 



Steel for slender tools. 

of pressure, a steel low in carbon may be used. Any- 
desired amount of surface hardness may be given the 
piece. If, however, the tool will be subjected to tor- 
sional strain, as in the case of a long, slender reamer, 
or if it may have to resist a crushing strain, as in the 
case of a punch press forming die, it is necessary to use 
stock containing sufficient carbon to furnish the desired 
result when hardened. If the tool is not to be subjected 
to very great strain, almost any low grade stock that is 
practically free from impurities will do. 

If a long, slender reamer, or similar tool, is to be 
made, excellent results are claimed by using a low 
grade steel of 40-point (.40^) carbon. In the case of a 
forming die, or similar tool, use a steel of 60 to 80-point 
carbon. If, however, it was to be subjected to great 
pressure or very severe usage, the writer's experience 
leads him to advocate the use of tool steel specially 
adapted to this class of work. 

As it is necessary, in order to get satisfactory re- 
sults, to have the percentage of impurities as low as 
can be obtained, in order to have the hardened steel as 
strong as possible, do not allow it to come in contact 
with any form of bone when heating. The articles should 
be packed in a hardening box with a mixture of equal 
quantities (volume) of charred leather and granulated 
charcoal in the same manner as described under Pack 
Hardening. It will be necessary to subject the articles 
to heat for a longer period of time than if hardening 
tool steel. The length of time the articles are sub- 
jected to the action of the carbonizing element depends 
on how deep it is necessary to have the hardened portion. 
The test wires previously mentioned should be used 
to determine when the contents of the box are heated. 

*73 



When in doubt about steel. 

If you are reasonably sure the steel used was prac- 
tically free from injurious impurities and is low in car- 
bon, it may be dipped in a bath of water or brine. 
Should there be any doubt as to this, dip in raw lin- 
seed oil. 

If the article being hardened is a cutting tool, or 
something requiring a fine, compact grain, better re- 
sults will follow if it is left in the box after being sub- 
jected to the action of carbon, the box removed from 
the fire, and the whole allowed to cool. When cold, 
the article may be reheated to a low red, and hardened. 

While the writer has used a low grade steel in 
making various forms of tools, and had excellent re- 
sults when they were put to the use for which they 
were intended, he cannot recommend its use, unless the 
parties doing the work select stock suited to the pur- 
pose and exercise due care when hardening. 

While this subject might properly be classed under 
the heading of Case Hardening, it has not seemed wise 
to the writer to do so, because case hardening, according 
to the interpretation usually given it by mechanics, is 
simply a process of transforming the surface of the 
article into a condition that allows it to become hard if 
plunged red-hot into water. Hardness is apparently 
the only object sought, but such is not the case when 
the subject is considered in its proper light. 

When applying this principle to tools, it is neces- 
sary to consider the requirements of the tools. Know- 
ing this, it is necessary to proceed in a manner that 
will give the desired results. 

If it is considered advisable to make certain tools 
of a low grade steel, treating it as described, it is 
necessary to select steel adapted to the tool to be made. 

274 



Special steels. 

It is never advisable to use Bessemer steel bought in 
the open market, because it does not run uniform. 
Always use open hearth steel, procuring it, if possible, 
of a quality that will give satisfactory results. Steel, 
with a very small percentage of phosphorus and other 
impurities, may be obtained from any reliable maker, 
if the purpose for which it is to be used is stated when 
ordering. 



Special Steels. 




CO 



To one interested in working steel, the history of 
the development of this industry furnishes a remarka- 
bly interesting study. 

Steel may be grouped under four general heads, 
the name given each class being selected on account of 
the method pursued in its manufacture. 

Probably the oldest of all known steels is the 
cemented or converted steel. This steel is made by 
taking iron in the form of wrought iron bars, packing 
them in a fire-brick receptacle, surrounding each bar 
with charcoal. This is hermetically sealed, and heat 
is then applied until the whole is brought to a degree 
of heat that insures the penetration of a sufficient 
quantity of carbon. Experience proves that carbon 
will penetrate iron at about the rate of one-eighth of 
an inch in twenty-four hours; and as bars of about 
three-quarter inch thickness are generally used, it re- 
quires three days for the carbon to penetrate to the 

Z75 



Crucible cast steel. 

center of the bar (3-6 -inch). The furnace is then al- 
lowed to cool, and the iron bars, which are converted 
to steel, are removed. They are found to be covered 
with blisters, hence the name, Blister Steel. 

When examined, the bars are found to be highly 
crystalline, brittle steel. When this form of steel is 
heated and rolled directly into commercial bars, it is 
known as German Steel. 

If blister steel is worked by binding a number of 
bars together, heating to a high heat, and welded under 
a hammer, it is known as Shear Steel, or Single-Shear. 

If single-shear steel is treated as above, the finished 
product is known commercially as Double-Shear Steel. 

Until within a comparatively few years these three 
classes of converted steel were practically the only 
kinds known in commerce. 

Crucible Cast Steel. 

As this is the standard steel used for fine tools, a 
brief study of the methods used in its manufacture 
may be of interest to the reader. Benjamin Huntsman, 
a clockmaker, is supposed to have been the inventor of 
this process. It occurred to him that he might pro- 
duce a more uniform and satisfactory article than was 
to be had at that time for use in manufacturing springs 
to run his clocks. The method he had in mind con- 
sisted in charging into a crucible broken blister steel, 
which was melted to give it a homogeneous character. 

While Huntsman thus founded the crucible steel 
industry, which has been of incalculable value to the 
mechanic arts, he met with many difficulties. These 
have been overcome by later inventions, notably those 

276 



Alloy steels. 

of Heath and Mushet, until to-day it is possible, with 
skill and care, to produce a quality of steel which, for 
strength and general utility, has never been equaled, 
despite the claims of some blacksmiths that the steel of 
to-day is not as good as that produced 25 to 50 years ago. 
Competition has rendered it necessary to run cut- 
ting tools, or stock, as the case may be, much faster 
than was formerly the case, which made it necessary to 
make steel containing a higher percentage of carbon 
than was formerly the case. As stated in a previous 
chapter, when high carbon steels are used, it is neces- 
sary to exercise great care in heating for the various 
processes of forging, annealing and hardening, As 
high carbon steels are more easily burned than those 
containing a lower percentage, it is necessary to put 
them in the hands of skilled workmen, for, unless the 
steel is to be worked by men understanding its nature, 
it proves to be a very unsatisfactory investment, and 
is often condemned because it will not stand as much 
abuse as a steel of lower carbon; but if properly 
treated, will do many times the amount of work. 



Alloy Steels, 



In order to accomplish certain results, steel is made 
containing other metals. To distinguish them from 
steels, which depend on the quantity of carbon present 
for their hardening properties, they may properly 
be termed "alloy" steels, the amount of the hardening 
property present determining the quality of the 
steel. As these steels can generally be run at a higher 
periphery speed and cut harder metals than carbon 
steels, they are very valuable at times, and in some 

277 



Self-hardening steel. 

shops are used altogether. As a rule, they are more 
easily injured by fire than carbon steel, and, conse- 
quently, extreme care must be exercised when working 
them.. 

When high carbon steel is alloyed with other hard- 
ening properties, a steel is produced which will be found 
more efficient for machining chilled iron than the 
regular high carbon steels. However, as the nature of 
steel of this character depends entirely on the amount 
and kind of the alloy used and the amount of carbon 
present, no fixed rule can be given for the treatment. 
It is always best to follow as closely as possible direc- 
tions received with the steel. 

The writer has seen milling machine cutters, punch 
press blanking dies, and other tools, which were to cut 
very hard, "spotty" stock, give excellent results, when 
made from a reliable alloy steel, where carbon steels 
would not stand up. 

If the amount of certain hardening elements be 
increased to a given point, the steel hardens when 
heated red-hot, and is exposed to the air. It is styled 
"Air Hardening Steel, " more generally known, how- 
ever, as Self-Hardening Steel. 

Self-hardening Steel. 

It was not originally the intention of the writer to 
mention self-hardening steel, because there are so many 
different makes of the article, each differing from the 
other to an extent that the method employed to get sat- 
isfactory results, when using one make, would prove 
entirely unsatisfactory when applied to another. 

Self-hardening steel has a field of its own, and is 
very useful when made into tools for certain work. It 

278 



A common error. 

is used very extensively in cutting hard metals, and 
can be run at a high periphery speed, because the heat 
generated does not soften the tool, as is the case when 
carbon steels are used. 

No general instructions can be given for working 
the steel, because the composition of the different makes 
varies so much that the treatment necessary, in order 
that one brand may work satisfactorily, would unfit 
another for doing the maximum amount of work pos- 
sible for it to do. 

A very common error in shops where a make of 
this steel is used, and another brand is to be tried, con- 
sists in attempting to treat the new brand in the same 
manner they have been treating the other, regardless 
of instructions furnished. 

As previously stated, the treatment suited to one 
brand would render another unfit for use, and as the 
reputation of a brand depends on the results attained, 
the makers are very careful when selling steel to state 
plainly the treatment it should receive. The buyer 
should see that the directions are followed implicitly. 

When purchasing self -hardening steel, it is advisa- 
ble to investigate the merits of the different makes. In 
practice, certain brands prove best for cutting cast 
iron, while another brand, which will not do as much 
work when cutting cast iron, proves to be more desira- 
ble when working steel. Other brands, which give sat- 
isfaction when made into lathe and planer tools, prove 
useless when made into tools having projecting cutting 
teeth, as milling machine cutters, etc. 

As previously stated, the different makes of self- 
hardening steel require different methods of treatment. 
One gives best results when worked (forged) at a full 

279 



A few don'ts. 

red heat, while another requires a much higher heat. 
As the steel is less plastic when red-hot than most 
carbon steels, it is necessary to use greater care in re- 
gard to the manner in which it is hammered. A heavy 
hammer should be used, if a large section is to be forged, 
as it is necessary to have it act uniformly on the entire 
mass, or the surface portion will be drawn away from 
the interior, and, as a consequence, a rupture will be 
produced. Small pieces should be forged with lighter 
blows, or the steel will be crushed. 

Do not attempt to forge when the temperature is 
lowered to a point where the steel loses its malleability, 
or it will be injured. 

It is very necessary that a uniform heat be main- 
tained throughout the piece. Do not think, when work- 
ing a small section, that it is safe to forge when it has 
cooled to a low red, because some heavier portion has 
not cooled below a full red. 

Do not allow the steel to cool off from the forging 
heat. After forging, place the piece in the fire again, 
and allow it to come to a uniform bright red. Do not 
allow it to "soak" in the fire, but it should be heated 
at this time without the aid of the blast. When it has 
reached a uniform red heat, remove from the fire, and 
allow it to cool in a dry place, not exposed to the action 
of any draft. 

While most self-hardening steels will become hard 
enough when cooled in the air, it is sometimes necessary 
to have the tool extra hard. In such cases, it may be 
cooled in a forced blast. Some steels give better re- 
sults if cooled in oil, others require cooling in hot oil, 
while others may be cooled in hot or cold water. Gen- 
erally speaking, however, it is not advisable to bring 



Different steels need different treatment. 

most brands of this steel in contact with water when 
red-hot. 

While it is generally admitted that self-hardening 
steels are principally valuable for lathe, planer, and 
similar tools, when cutting hard metals or running at 
high speeds, there are makes which give excellent sat- 
isfaction when annealed and made into such tools as 
milling machine and similar cutters. 

When it is necessary to have the stock in an an- 
nealed condition, it is advisable to procure it in this 
state, as the manufacturer, understanding the composi- 
tion and nature of the steel, is in a position to anneal 
it in a more satisfactory manner than the novice. How- 
ever, if it is considered advisable to anneal it in the 
factory where it is to be worked, it may be accom- 
plished. Different makes of steel require treatments 
differing from each other, the treatment depending on 
the element used to give it its hardening qualities. 
Some brands may be annealed sufficiently to work in 
the various machines used in working steel to shape 
by heating to a bright red and burying in green pine 
sawdust, allowing it to remain in the sawdust until cool. 

Most brands may be annealed by keeping the steel 
in an annealing furnace at a bright red heat for from 
twenty-four to forty hours, then covering with hot sand 
or ashes in the furnace, and allowing to cool. It should 
be about the same length of time cooling as it was ex- 
posed to the heat. It is necessary many times to 
machine it with tools made of the same quality of steel, 
on account of the natural hardness and density of the 
stock. It is claimed that tools made of certain brands 
of 'jelf-hardening steel give better results when cutting 
chilled iron than tools made of high carbon alloy steels, 



Get reliable steel. 

The writer cannot substantiate this claim, as he has 
never been able to get as good results as when using an 
extra high carbon alloy steel, properly treated. 

However, it is safe to say that used for machining 
(roughing) work in the lathe, planer, and similar 
machines, can be made to do many times the amount 
of work in a given time than would be the case were 
ordinary carbon steel tools used. 

Much better results may be attained, however, than 
is usually the case, if makers' instructions are implicitly 
followed. 

On account of the rapidly growing popularity of 
certain makes of this class of steel, many swindles 
have been perpetrated by unscrupulous parties, claim- 
ing to be representatives of a reliable house. A tool 
made, as they claim, from the steel they were selling 
is submitted for trial. It proves to be all that could 
be asked for, and a quantity of steel is ordered sent 
C. O. D. When this is received and paid for, it is found 
to be of no use. Parties purchasing steel of any but 
known and reliable steel concerns do so at a great risk, as 
a number of manufacturers have found to their sorrow. 

Steel for Various Tools. 




There is no one topic connected with this work that 
caused the writer so much anxiety as the one under 
consideration, because a temper of steel that gives en- 
tire satisfaction when used in one shop, would not 
answer when made into tools intended for the same, or 

282 



Phosphorus in steels. 

similar purposes, in a shop situated on the opposite 
side of the street. This is simply because in one case 
the operator who forged or hardened the tools under- 
stood handling the steel, and in the other case a man 
totally incompetent was entrusted to do the work. 

Then again, steels of certain makes are more free 
from harmful impurities than others. A steel contain- 
ing a low percentage of these impurities can safely have 
a higher percentage of carbon. Certain steels which 
are low in their percentage of phosphorus can have a 
greater amount of carbon than other steels which con- 
tain more of this harmful impurity. 

A tool made of 1.4 per cent, carbon steel low in 
phosphorus will not cause as much trouble as if made 
of a 1.25 per cent, carbon steel containing a greater 
amount of phosphorus, but its capacity for cutting hard 
metals, and holding its edge when running at high 
speeds, is much greater. 

Knowing the tendency in many shops to use a high 
carbon steel, and realizing the advantages of so doing, 
the writer would advocate the use of such steels, were 
it not for the fact in many cases the results have been 
anything but satisfactory, because men totally unfit for 
such work were employed to forge and harden the tools 
made from them. 

But it has seemed wise to give the tempers of tool 
steel suited for certain purposes, the reader bearing in 
mind that in many cases it is safe and advisable to use 
a higher carbon, provided due care is exercised when 
working it during the various operations of forging, 
annealing and hardening. As previously stated, steel 
of a certain make and temper giving excellent results 
in one shop does not always give satisfactory results in 

283 



The degrees of hardness. 

some other shop on the same class of work. Knowing 
from experience that the variable factor is the man 
working the steel, rather than the steel itself, the writer 
has deemed it wise to quote the experience of various 
steel makers, rather than results of his own personal 
experience. 



Degree of Hardness 


Percent- 
age of 
Carbon 


Should be used for 


Very hard 


i-5 


Turning and planing tools for 
hard metals, small drills, 
gravers. 


Hard 


1-25 


Tools for ordinary turning and 
planing, rock drills, mill 
picks, scrapers, etc. 


Medium hard 


i. 


Taps, screw thread dies, 
broaches, and various tools 
for blacksmiths' use. 


Tenaciously hard 


•85 


Cold sets, hand chisels, ream- 
ers, dies, drills. 


Tough 


•75 


Battering tools, cold-sets, shear 
blades, drifts, hammers, etc. 


Soft 


•65 


Battering tools, tools of dull 
edge, weld steel for steeling 
finer tools, etc. 



While the foregoing table gives the tempers of 
steel that can safely be used for the purposes specified, 
it is many times advisable to use steel of a higher per- 
centage of carbon. 

Then again, it is sometimes best to use a low carbon 
steel of good quality, in order to get the maximum 
amount of toughness in the interior portions, packing 
the finished tool in a box containing charred leather, as 

284 



How to make steel extremely hard. 

explained under Pack Hardening, and running for a 
sufficient length of time to get an extremely hard sur- 
face when hardened. By adopting this method, it is 
possible to get a cutting surface that will stand up when 
running at a high rate of speed, and yet be strong 
enough to resist extremely rough usage. 

When it is desirable to get the steel extremely hard 
and very deep, in order to allow for grinding, and yet 
have the tool sufficiently tough to stand up, use a high 
carbon steel, pack in a box as described, running in the 
fire at an extremely low heat ; quench in a bath of raw 
linseed oil. 

In order to provide a guide for use in selecting 
steel suitable for various purposes, the following list 
is given. It is the result of the writer's experience, and 
information picked up here and there. A very notice- 
able fact, however, must be taken into consideration, 
namely: mechanics in the same class do not advocate 
the use of steel of like tempers, even when making tools 
of the same kind, to do the same class of work under 
the same, or similar circumstances, so no rule can be 
given arbitrarily. 

The reader should, however, bear in mind that 
steels, which contain impurities to any considerable de- 
gree, cannot safely be used with the percentage of 
carbon mentioned. But as most of the leading steels 
on the market have received their standing because they 
are practically free from these impurities, it is safe 
when using them to use the percentages of carbon 
mentioned. 

There are several makes of crucible tool steel 
on the market, which are exceptionally low in their 
percentage of impurities, and when using these, it is 

285 



About cast steel. 

safe to use a higher carbon than the one mentioned, 
provided due care is used when heating for the various 
operations of forging, annealing and hardening. 

In the following pages the term crucible steel is 
intended to denote crucible tool cast steel. 

The term cast steel is often misunderstood by me- 
chanics, and many are of the opinion that any cast steel 
is tool steel. Such, however, is not the case, for the 
products of the Bessemer and open hearth processes 
are cast steel in the same sense that crucible steel 
is, yet they are not understood as tool steels, although 
products of both processes which were highly carbon- 
ized have been sold to parties as tool steel. 

Arbors for saws. 
Saw arbors, and similar articles, when made from 
crucible steel are made from a stock containing .60 to 
.70 per cent, carbon. When made from open hearth 
steel the percentage of carbon is about the same, 
although some manufacturers claim good results when 
a lower percentage is used. 

Arbors for milling machines. 
Milling machine arbors when made from crucible 
steel give good satisfaction if a steel of .70 to .80 per 
cent, carbon is used. Unless they are to be hardened, 
better results are obtained if the steel is worked to 
shape without annealing, as it is much less liable to 
spring when subjected to strain in use. In shops where 
great numbers of these arbors are used crucible steel 
is considered very costly. In such cases open hearth 
steel containing .40 to .60 per cent, carbon is often 
used. Many times a stock containing a higher per- 
centage is used. 

286 



Augers. 
Augers for wood-work are made from crucible 
steel of . 70 to .80 per cent, carbon, 

Axes 
are made from crucible steel containing - 1 00 to 1.20 
per cent, carbon. 

Barrels for Guns 
are made from crucible steel containing- .60 to .70 pei 
cent, carbon, while some manufacturers use an open 
hearth steel containing .50 per cent, carbon, and others 
claim to use the same steel with . 60 or even . 70 per cent. 

Centers for Lathes 
are made of crucible steel containing .90 to 1.10 per 
cent, carbon. 

Chisels for Working Wood 

are made from crucible steel containing 1.15 tc 1.25 
per cent, carbon. 

Chisels for Cutting Steel, 

where the work is light, give good satisfaction when 
made from crucible steel containing 1.25 per cent, 
carbon. 

Cold Chisels, 

for chipping iron and steel, work well if made from 
crucible steel containing .90 to 1.10 per cent, carbon. 
Trouble with cold chisels is more often the result of 
poor workmanship than an unsatisfactory steel. 

Chisels for Hot Work 

may be made of crucible steel of .60 to .70 per cent, 
carbon. 

287 



Chisels • for Cold Work, 

for blacksmiths' use, are made of crucible steel con- 
taining .70 to .80 per cent, carbon. 

Chisels for Cutting Stone 
are made from .85 per cent, carbon crucible steel. 

Cutters for Milling Machine Work 

are probably made from a greater range of tempers than 
almost any other tool used in machine shop work, 
some manufacturers never using a steel containing over 
1. 00 per cent, of carbon, on account of the liability of 
cracking. Cracking is, however, a result of careless 
working, and as much more work can be done in a given 
time with a cutter made from a high carbon steel, it 
is, generally speaking, advisable to use such steels. 
Cutters, 2 inches and smaller, may safely be made from 
crucible steel containing 1.25 to 1.40 per cent, carbon. 
Cutters, 2 to 3 inches, 1.15 to 1.25. Larger than 3 
inches, or if of irregular contour, 1. 10 to 1.20 per cent, 
carbon. There are several alloy steels on the market 
which give excellent results when made into cutters of 
this character, provided extreme care is taken in 
heating. 

Cutters for Pipe Cutting 

may be made from crucible steel containing 1.20 to 
1.25 per cent, carbon. 

Cutters for Glass 

are made from crucible steel containing 1.25 to 1.40 
per cent, carbon. 

*88 



Dies (Threading) for Bolts 

and similar work, made from stock having rough, un- 
even surfaces, may be made from crucible steel con- 
taining . 70 to . 80 per cent, carbon. However, when the 
dies are hardened by the process described under Pack 
Hardening, steel containing 1.00 to 1. 10 percent, works 
nicely, stands well, and holds a good edge. 

Dies for Screw Cutting, 

to be used by hand or in screw machine, may be made 
from crucible steel containing 1.00 to 1.25 percent, 
carbon. 

Dies for Blanking or Punch Press 
work are made from crucible steel Containing .90 to 
1. 10 per cent, carbon. When the articles to be punched 
are small, and the stock to be worked is hard, steel con- 
taining 1. 00 to 1.25 stands better than the lower carbon 
steel for small dies. Some manufacturers use a steel 
containing 1.25 to 1.40 per cent, carbon, provided it is 
low in percentage of impurities. When the work is 
not of a shape that requires great strength on the part 
of the die, open hearth steel containing .40 to .80 per 
cent, carbon is used. The die in this case should be 
hardened according to directions given for hardening 
tools made from machine steel. 

Dies Used for Swaging 

metals are made from crucible steel, the percentage of 
carbon varying according to the character of the work 
to be done. When the die is not to be subjected to 
very severe usage, a steel containing .90 to 1.10 per 
cent, of carbon may be used. Where a deeply hard- 
ened portion is desirable, a steel containing 1. 20 to 1.25 
per cent, works nicely. 

289 



Drawing Dies 

are made of crucible steel containing 1.20 to 1.25 per 
cent, carbon. 

Dies for Drop Forging. 

As the product of different steel manufacturers 
varies so much, and the requirements are so varied for 
work of different kinds, it is advisable to submit the 
article to be made to some reliable steel manufacturer, 
letting him furnish a steel especially adapted to the 
work to be done. Ordinarily a crucible steel is used 
containing .40 to .80 per cent, carbon. However, many 
manufacturers consider it best to use a good quality of 
open hearth steel containing the proper percentage of 
carbon. Small dies, or those having slender portions 
requiring great strength, are made of the higher carbon.. 

Drills— (Rock Drills), 

for quarry work, are made of crucible steel containing 
1. 10 to 1.25 per cent, carbon. 

Drills— (Twist). 

Small drills are made of crucible steel of 1.25 to 
1. 50 per cent, carbon, while larger drills require a steel 
of 1. 00 to 1.25. 

Files 

are made of crucible steel of 1.20 to 1.40 per cent, car- 
bon. Files of inferior quality are made of open hearth 
steel. 

Hammers for Blacksmiths 

use are made from crucible steel of .65 to .75 per cent, 
carbon. 

290 



Hammers for Machinists' 

use are made from crucible steel of .85 to 1.15 per 
cent, carbon. For the ordinary sizes steel containing 
1. 00 per cent, works nicely. 

Hardies for Blacksmiths 
are made of crucible steel of .65 to .75 per cent, carbon. 

Hobs for Dies 

are made of crucible steel of . 90 to 1.00 per cent, carbon, 
when they are to be used for cutting a full thread in a 
die. If they are to be used for sizing only, a steel 
containing 1.20 to 1.25 may be used, as it will hold its 
size and form longer than if made of steel containing 
less carbon. 

Jaws for Bench Vises 

are made from crucible steel of .80 to .90 per cent. 
carbon. Open hearth steel is, however, extensively 
used for this purpose. 

Jaws for Chucks 

are strongest if made of crucible steel containing .85 
to 1. 00 per cent, carbon, although many times they are 
made from a good quality open hearth steel. 

Jaws for Cutting Pliers 

are made from crucible steel containing 1.10 to 1.25 
per cent, carbon. When they are to be used for cutting 
piano or other hard wire, they are made from steel 
containing 1.40 to 1.50 per cent, carbon. 

291 



Jaws for Gripping 

work in various fixtures are made from crucible steel 
of .80 to .90 per cent, carbon. 

Jaws for Pipe Machines 

are made from crucible steel containing 1.00 to 1.20 
per cent, carbon. 

Jaws for Screw Threading Dies, 

having' inserted jaws or blades, are made of crucible 
steel of 1. 00 to 1.20 per cent, carbon. 

Jaws for Wire Pullers 

are made from 1.00 to 1.20 per cent, carbon crucible 
steel. 

Knife Blades. 

When crucible steel is used, a stock containing .9 
to 1. 00 per cent, carbon is selected. 

Knife Blades, 

to be used for whittling and general wood-working, are 
made from i.ioto 1.25 per cent, carbon crucible steel. 

Knives — Draw Knives 

are made from crucible steel of 1.20 to 1.25 per cent, 
carbon. Many times, however, they are made of open 
hearth steel. 

Lathe Tools 

for ordinary work are made of crucible steel containing 
1.25 per cent, carbon. For turning hard metals or 
running at high rate of speed, use steel containing 
1.40 to 1.60 per cent, carbon. 

292 



Lathe Tools. 

For turning chilled iron, a high carbon alley stee! 
works better than a straight carbon steel. 

When it is desirable to run at very high speeas, 
use a self -hardening steel. 



L ^5 



Machinery Crucible Steel 
contains .55 to .65 per cent, carbon. 

Mandrels. 

Custom differs in various shops. Some mechanics 
consider it best practice to make mandrels up to and 
including 1 inch of crucible steel, and for sizes above 1 
inch advocate the use of machine steel, case hardened. 
Others claim best results from crucible tool steel for 
all sizes. Mandrels, however, do not require a steel 
containing as high a percentage of carbon as cutting 
tools. Small mandrels give good satisfaction when 
made from steel of from 1.00 to 1.10 carbon, larger 
sizes made of steel containing .80 to 1.00 per cent. 

When mandrels are hardened by the process known 
as Pack Hardening, a steel containing .75 to .90 per 
cent, will give excellent results. 



M 



owers. 



Lawn mower knives, .90 to 1.00 per cent, crucible 
steel, although in many instances they are made from 
open hearth steel. 

Planer Tools for Stone, 
•75 to .90 per cent, carbon crucible steei. 

Planer Tools for Wood-working 
machinery are made of crucible steel containing from 
i.ig to 1.25 per cent, carbon. 

293 



Planer Tools. 

If the tools are large and the metal to be machined 
is comparatively soft, crucible steel containing 1.25 
works nicely. If, however, high speeds are desired or 
the metal to be cut is hard, a steel containing 1.40 
to 1.50 per cent, carbon gives better results, provided 
care is exercised in heating for forging and hardening. 
If the stock to be cut is extra hard or it is desirable to 
run at speeds higher than is practical when using tools 
made from carbon steels, it is advisable to get a reliable 
self-hardening steel. 

Punches for Hot Trimming, 

.85 to 1. 00 percent, carbon crucible steel. Some mechan- 
ics claim as good results if the punch is made of open 
hearth steel of .60 to .80 per cent, carbon, while others 
make both punch and die of open hearth steel. These 
tools may be hardened in the ordinary manner or they 
may be hardened according to directions for hardening 
tools made of machine steel. 

Punches for Blanking Work 

in punch press. The percentage of carbon desirable 
depends on the stock to be cut and the skill of the 
operators doing the hardening If crucible steel is used, 
a range of .90 to 1.25 per cent, carbon is allowable, de- 
pending on the character of the work. Many times, 
however, such punches, if of a shape and size that in- 
sures strength, are made of .40 to .80 per cent, carbon 
open hearth steel, and hardened as explained under 
Making Tools of Machine Steel. 

Punches for Blacksmiths 
should be . 80 to . 90 per cent, carbon crucible steel 

294 



Punches for Railroad Track Work, 
about .'85 per cent, carbon crucible cast steel is advis- 
able. 

Reamers. 
Small reamers, which are to be used continuously, 
should be made from crucible steel of 1.25 to 1.50 per 
cent, carbon. When they are to resist great strain, 
steel of 1. 00 to 1.25 per cent, may be used. Excellent 
results will follow if steel containing .90 to 1.10 per 
cent, carbon is used, and the reamer hardened by the 
method described under Pack Hardening. This is es- 
pecially true if the reamer is long or slender, or of a 
shape that betokens trouble when it is hardened. 

Saws (Circular) for Wood, 
about .80 to .90 per cent, crucible steel. 

Saws for Cutting Steel 
are made from 1.25 to 1.50 per cent, crucible steel. 

Scrapers for Scraping Surfaces, 
1.50 carbon crucible steel. Although many scraper 
hands claim best results from using a high carbon alloy 
steel. 

Screw-Drivers, 
small, .90 to 1. 00 per cent, crucible steel; large, .65 to 
.80 per cent. 

Stamps for Stamping Steel, 
1.25 to 1.50 per cent, carbon crucible steel. 

Shafts for High Speed Machinery 
are many times made from crucible steel, containing 
.65 per cent, carbon. 

Spindle Steel, 
same as shafts. 

295 



Springs for Ordinary Purposes 

are made from i.oo to i.io per cent, carbon crucible 
steel. For many purposes, an open hearth steel is used 
with satisfactory results. 

Springs for Locomotives 

are made by some manufacturers of crucible steel con- 
taining .90 to 1. 10 per cent, carbon, and by others of a 
steel containing- .80 to .90 per cent., while in many 
cases very satisfactory results follow if open hearth 
steel, made especially for the purpose, is used. 

Springs for Carriages 

are made from crucible steel containing .80 to .90 pel 
cent, carbon, but many more springs of this character 
are made from open hearth and Bessemer stock than 
from crucible, because it answers the purpose and is 
much cheaper. 

Taps 

are made of crucible steel containing 1.10 to 1.25 per 
cent, carbon in many shops, while others claim "better 
results from steel containing 1.25 to 1.40 per cent. 

Taps for Tapping Nuts, 

generally called machine taps, give best results if made 
from steel containing 1.00 to 1. 10 per cent, carbon. 



296 



Causes of Trouble. 



CO 

While most of the causes of trouble when steel is 
hardened have been considered under the various 
topics presented, it has seemed wise to group together 
the more common causes, in order that they may be 
referred to more readily by the reader. 

Uneven Heats. 

Probably the most common cause of trouble is un- 
even heating of the piece in forging, annealing or 
hardening. As a consequence, violent strains are set 
up which cause the piece to crack or, in the case of 
heavy pieces, to burst. The different parts of the piece 
being unevenly heated, must, when cooled, contract 
unevenly; and when two portions of a piece adjoining 
each other attempt to contract unevenly — that is, one 
contracting more or faster than the other — and both 
being rigid to an extent that makes it impossible for 
them to yield one to the other, there must be a separa- 
tion at the point where the uneven temperature occurs. 

High Heats. 

A very common cause of trouble consists in heat- 
ing steel too hot for the purpose. High heats open the 
pores of the steel, making the grain coarse and causing 
the steel to be weak. When the piece is broken, it has 



Too rapid heating. 

a honeycomb appearance — looks full of holes, so to 
speak. Now 5 as there is but a very thin layer of steel 
over these holes, when pressure is applied the surface 
over the holes caves in, and the steel is unfitted for 
doing the maximum amount of work. 

Steel which has been overheated may be restored 
— unless the heat was high enough to burn or disinte- 
grate the steel — by reheating carefully to the refining 
heat and quenching ; but it can never do the amount of 
work possible, had it not been overheated. Yet, it will 
be much better than if left in the condition the high 
heat placed it. 

Then again, high heats have a tendency to cause 
the steel -to crack when hardened. This is especially 
true if the piece be cylindrical in shape. Cylindrically 
shaped pieces will not stand the amount of heat that 
may safely be given a piece of almost any other shape 
without cracking, although the effect on the grain and 
the ability of the steel to stand up and do the maximum 
amount of work possible would be the same in any case, 
regardless of the form of the piece or the method of 
applying the heat. 

Too Rapid Heating. 

While it is advisable to heat steel as rapidly as 
possible consistent with good results, it should not be 
heated too rapidly, as corners and edges will become 
overheated before the balance of the article has reached 
the proper heat ; and even if they are allowed to cool 
down to the proper heat (apparently), the grain has 
been opened at these portions, and violent strains are 
set up. This is one of the places where experience 
seems to be the only guide and where the instructor 

298 



Fire cracks — how to avoid. 

can only give suggestions, which should be heeded 
and worked out by each hardener. 

Heating Too Slowly. 

In attempting to avoid heating too rapidly, do not 
go to the opposite extreme and allow the steel to 
"soak " in the fire, or soft surfaces will result, and the 
steel is not as good as if heated properly. 

Fire Cracks. 

There are a number of causes for steel cracking in 
the fire. Among the more common are, first, the cold 
air from the blast, if the work is heated in a black- 
smith's forge. Then again, it may be heated in a gas 
flame having an air blast. The air may be turned on 
too much, resulting in cold air jets striking the heated 
steel. If a charcoal fire is used, it is the custom of 
some hardeners to throw cold water on the fire. Now, 
if the steel is red-hot, the water has a tendency to cause 
it to crack in the same manner as if the air from the 
blast came in contact with it. 

Large articles plunged in a crucible of red-hot 
lead, cyanide of potassium, or any substance where they 
are exposed to violent heats, are very liable to crack, 
especially if there are heavy and light portions adjoining 
each other. The unequal expansion tears the steel 
apart at the point where the unequally heated portions 
adjoin each other. This may be avoided by heating 
the articles nearly to a red in some form of fire where 
it would heat more slowly, then plunge in the lead to 
bring to the desired heat; or, the article maybe im- 
mersed in the red-hot contents of the crucible, left for 
a moment and withdrawn, immersed again, leaving a 

299 



Improper forging. 

trifle longer, and so continue until it reaches the 
desired heat. 

If a piece of steel is immersed in a crucible of red- 
hot lead or similar material for a certain distance so 
that part of the piece is out of the red-hot material, it 
should be moved up and down in the molten mass, or 
the part below the surface will expand more rapidly 
than the adjoining metal. If the article were lm. 
mersed and withdrawn, repeating this operation until 
the desired result is obtained, the heat being applied 
gradually, the expansion is more uniform, and the heat 
is imparted to the adjoining stock so it can yield to an 
extent that does away with any tendency to crack. 

Cold Baths. 

Extremely cold baths are the cause of a great deal 
of trouble when pieces of irregular contour are harden- 
ed. It is nearly always advisable, when hardening 
articles made of high carbon steel, to warm the con- 
tents of the bath somewhat. Many hardeners claim 
that oil heated to a temperature of ioo degrees to 120 
degrees will harden steel harder than if it were ex- 
tremely cold. It will certainly cause it to be tougher. 

Improper Forging. 

This is the cause of a great amount of trouble 
when steel is hardened. While the writer claims best 
results from steel properly forged, he is aware that 
much better results are obtained from steel machined 
to shape than if the articles were heated or hammered 
in any but a proper manner. 

Steel to be made into tools whose cutting edges 
are on or near the end should not be nicked with _ a chisel 

300 



A few more don'ts. 

and broken, as the portions at the end are rendered 
unfit for cutting purposes. 

Do not straighten steel that is to be hardened 
without heating it red-hot. 

Do not attempt to harden a tool of irregular shape 
unless it has been annealed after blocking out to some- 
where near to shape. 

Do not take it for granted that because you have 
held a piece of steel in the fire and stuck it into water, 
it is necessarily hard. Try it with a sharp file before 
brightening the surface preparatory to drawing the 
temper, as much valuable time may be saved if the 
piece should prove not to have hardened. 

When you get a piece of steel that you are in doubt 
about, it is advisable to cut a small piece of it from the 
bar and harden it, noticing the amount of heat neces- 
sary to produce desired results. If this is not done, 
trouble may follow when the article is hardened. It is 
better to experiment with a small piece of steel than 
with a costly tool. 

Do not use any but chemically pure lead in a crucible 
intended for heating tools, or you will not get as good 
results as you might otherwise have. 

Do not think that because the surface of red-hot 
lead appears to be at about the proper heat, that the 
contents nearer the bottom of the crucible are neces- 
sarily of the same temperature; because, generally 
speaking, the deeper you place a piece of steel in the 
contents of the crucible the hotter it becomes. Being 
ignorant of this fact, workmen spoil many valuable 
articles, and then think the lead has an injurious effect 
on the steel, not knowing that it is the amount of heat 
given rather than the method used in applying it that 

301 



Things to remember. 

caused the trouble. Impure lead will injure the sur- 
face of the steel, but will not alter the appearance of 
the grain if the temperature- is right. 

Remember that steel heated for annealing should 
not be subjected to heat for a longer period of time 
than is necessary to produce a uniform heat of the de- 
sired temperature. Steel overannealed does not work 
as well in the various operations of machining, neither 
will it harden and temper as satisfactorily as though 
properly treated. 

Remember that heating is a process of softening 
steel, and cooling is a hardening process. The slower 
the process of cooling is carried on the softer the steel 
will be; consequently, it is never advisable to place 
red-hot steel that needs softening in cold or damp lime 
or ashes. 

Always use a clean fire. Dirty slack fires are a 
source of a great amount of trouble, as they cause the 
surface of the steel to be covered with a sulphurous 
oxide. 

A fire of new coals should be used (when using a 
charcoal fire) for heating steel. Dead coals require 
more blast than is good for the steel. 

Ten pieces of steel are cracked as a result of 
uneven heating to every one that is the result of a 
defect in the steel. 

Do not think that because the surface of a hardened 
piece of steel is not scaled that it is not overheated. 
Every degree of heat given it above that necessary to 
produce the desired result unfits the steel for doing the 
maximum amount of work possible for it to do. 

Always harden on an ascending heat. Never heat 
a little too hot and allow to cool down to the proper heat, 

30a 



About carelessness. 

as the grain of steel remains in the condition the last 
heat leaves it. To refine, it is necessary to allow it to 
cool off, and then reheat to the proper hardening heat. 

It often happens that the hardener is blamed for 
things he is entirely innocent of. A man in this posi- 
tion is liable to have enough spoiled work to account 
for that is the result of his own carelessness or ignor- 
ance without being obliged to shoulder the short- 
comings of others. It may be that some careless 
blacksmith has forged a tool at heats which unfitted the 
steel for the purpose for which it was intended. He 
may have heated the steel too hot, and opened the 
grain, causing brittleness, or he may have had uneven 
heats when he was forging, thus setting up internal 
strains which would cause the steel to crack when 
hardened. Then again, the tool maker may have at- 
tempted to straighten the piece without heating it red- 
hot, in which case it is almost sure to spring when 
hardened. Or, in the case of a long reamer or tap, the 
flutes may have been milled with a dull cutter, which 
would, of course, get duller the longer it was used, with 
the result that by the time the last flute was milled the 
tool would have been stretched very materially. This 
is especially true on the side where the last cuts were 
taken, as the cutter would be duller than when the 
flutes on the opposite side were milled, and the uneven 
stretching of the stock would, of course, spring the 
reamer. 

Another difficulty would also present itself. The 
dull cutter would glaze the surface of the tooth that 
came in contact with the dulled portion of the mill, and 
any surface of steel which is glazed, whether it be from 
the action of cutting tools or grinding wheels, will not 

303 



The effect of not paying attention. 

harden in a satisfactory manner. This difficulty is 
more pronounced in the case of a piece glazed from the 
action of grinding wheels. While a glazed surface 
might not be considered objectionable, if it was to be 
ground away after hardening, yet it is not always con- 
sidered advisable to grind the cutting faces of reamer 
and milling machine cutter teeth. There is no good 




.The Derry Collard Co. 

Figure 156. The spring of a mandrel. 

excuse for using dull tools when machining steel. Not 
only does it lead to trouble when the pieces are hard- 
ened, but it is a means of wearing the tools out much 
faster than if they were kept sharp. Neither can as 
much nor as good work be done with dull tools. 

It is often the case that a careless workman will 
mill the flutes in a long reamer, tap, or similar tool, 
without supporting the work properly. In this way the 
tool is sprung, first one way, then the other. This not 
only results in a crooked tool, but there is no knowing 
where it may go when hardened. Many times hard- 
ened pieces are sprung by heating when grinding. 
This is especially true with pieces that may have sprung 
when hardened. Take, for instance, a long mandrel 
which may have gone in the direction shown in Fig. 156. 
Now, if this mandrel were placed in a grinder and 
ground in a manner that caused it to become heated on 
the side that is already curved out, as shown in cut, it 
would spring still more. 

Many times thin, flat pieces are sprung from the 

304 



What caused the cracks. 

expansion of one side when ground in a surface 
grinder. The side which comes in contact with the 
wheel becomes heated, while the opposite side, from 
contact with a mass of cold iron — the table — remains 
cool. The side which heats must expand, with the re- 
sult that the piece is curved in the direction of the heated 
side. 

When flat pieces which are hardened are ground 
with a glazed wheel or one too fine for the purpose, 
they are very liable to crack, commencing at the edge 
or end where the wheel leaves the work. Fig. 157 re- 
presents a rectangular gauge which cracked as a result 





The Derry Collard Co. 



Figure 157. Cracked gauge. 



of grinding. The fault was laid at the hardener's door, 
and he, poor fellow, was doing his best to harden the 
gauges in a satisfactory manner, so he said the steel 
was no good. An investigation showed the cracks to be 
from the end where the wheel left the gauge when 
grinding in the surface grinder. The vise which held 
the piece was turned one-quarter way around, and it 
was found that the cracks were from one side, instead 
of the end of the piece. An examination of the wheel 
revealed the fact that it was too fine for the purpose, 
and that it was badly glazed. A coarse wheel, free from 

3°5 



Cracking from the wrong use of wate?. 



glaze, was substituted and the gauges were found to be 
sound after grinding. 

Not only may hardened steel be sprung and cracked 
from heat generated when grinding, but it may also be 
cracked if water is run on it, unless due care is observed. 
If the operation is hurried to the extent that it becomes 
heated, even when the water is running on it, the water 
cools the piece, which is instantly heated again and 
then cooled. This sudden expansion and contraction 
causes the steel 
to become 
cracked in 
innumerable 
places, these 
cracks running 
in all directions. - 
This trouble 
may occur when 
grinding pieces 
of almost any 
shape. The 
cracks may oc- 
cur on the sur- 
face of a cylin- 




The Derry Collard Co, 



Disc cracked from being 
ground too rapidly. 



drical piece, on the flats of a square, or on the face of 
an article being ground. Fig. 158 represents a disc 
whose face was cracked, as represented, when ground, 
with a stream of water running on the work. The fault 
did not lay in using water, but in forcing the grinding 
faster than the wheel could properly cut the metal. 

These few facts are pointed out, because it often 
happens that when these troubles arise, the party doing 
the hardening is blamed, and unless he is sufficiently 

306 



A proper emery wheel for cutter teeth. 

versed in the action of emery wheels on surfaces of 
steel, he naturally thinks the fault is either in the steel 
or in his method of treating it. 

Very often milling machine cutter teeth are soft- 
ened when ground, the hardener being blamed as a con- 
sequence. It is not good practice to use a very fine 
wheel when grinding tools of this description, neither 
should too hard a wheel be used. Ordinarly an emery 
wheel made of 60 to 90 emery will be found about 
right, and be sure the face of the wheel is not glazed. 
Should it become glazed, use a piece of emery wheel 
somewhat coarser than the one in use to remove the 
glaze. This also makes the face of the wheel open, 
and lessens the liability of heating. 

Many times the writer has seen workmen using a 
tool ground in a manner that made it impossible for it 
to cut. It was forced into the stock, and broke it off. 
The tool could not stand this treatment, and gave right 
out, the workman in the meantime saying things about 
the hardener. When the tool was properly ground, it 
worked all right. 

Some mechanics do not seem to realize that there 
is a proper speed to run stock or cutting tools, in order 
to get desired results. As a consequence, they either 
run them much too fast, with the result the tools can 
not stand up, or they are afraid they will exceed the 
proper speed, and, as a consequence, do not produce 
anywhere near the amount of work they might. 

When cutting a key way or spline in a tool that 
is to be hardened, the tool maker should avoid sharp 
corners, as they are an invitation for a crack when the 
steel is rapidly cooled in the bath. While an article 
having sharp corners is not as liable to crack when 

307 



How tools are weakened by grinding. 

hardened by the process termed Pack Hardening as 
when treated in the ordinary manner, it is not advisable 
to in any way weaken a tool, or give it an invitation to 
crack. Consequently, avoid sharp corners as far as 
possible, or cuts or deep scratches that tend to weaken 
the article. 

A milling machine cutter, made with light, weak 
teeth, can not be made to stand up when in use ; the 
teeth being slender and weak, break like pipe-stems. 
Cutters with teeth of this description require greater 
care when hardening, to avoid overheating. Being 
slender, they spring and break. Do not blame the 
hardener if they fail to give satisfaction when in use. 

Another source of trouble is fine teeth in milling 
cutters, reamers, and similar tools. The teeth, being 
fine, fill with chips, and in the case of milling machine 
cutters, the oil not being able to get to the teeth, can 
not conduct away the heat generated, which has the ef- 
fect of drawing the temper to a degree that makes it 
impracticable to use them. 

A short time ago the writer's attention was called 
to a side tool for use in an engine lathe. The tool was 
made from a well-known brand of steel, which is gen- 
erally considered one of the best steels on the market. 
It was claimed that the tool could not be made to keep 
an edge on a mild grade of machine steel running at a 
periphery speed of 30 feet per minute, taking a fair cut. 

An examination of the tool revealed the fact that 
it was ground in such a manner that the cutting edge 
had no backing. It might possibly have stood up 
if the material being machined had been wood in- 
stead of steel. Because the tool would not stand, 
the hardener was considered as being to blame. When 

308 



Why reamers, broaches, etc., break. 

properly ground, it stood up all right without re- 
hardening. 

Milling machine cutter teeth are many times ground 
with too great an angls, and the cutting edge, not having 
backing, gives way. Or it may not be given as much 
clearance as it should have. As a consequence, the heel 
of the tooth rubs, and the friction resulting trom this 
contact of the heel of the tooth with the material being 
machined produces heat, which softens the tooth. It 
is tried with a file, found to be soft, and the hardener 
is blamed. 

Many times the liquid supplied to keep cutting tools 
cool, and to lubricate the cutting edges, can not reach 
the cutting edges of the tool. As a consequence, it 
becomes heated and the temper drawn. This is es- 
pecially liable to happen to tools used on automatic 
screw machine work, where heavy cuts are being taken. 

Twist drills, used in drilling very deep holes in 
steel, are very liable to receive insufficient lubrication, 
unless supplied with oil tubes, because the oil which 
is fed down the flute is forced back by the action of the 
chips and the angle of the flutes. 

Taps are allowed to become clogged with chips, and 
break ; the hardener is blamed, because the tap, it is 
claimed, is too hard. Broaches break from the same 
cause, and the trouble is placed at the hardener's door. 
Reamers are allowed to become clogged, the cutting 
edge chips off, and it is said the steel is burnt. 

Cases of this character might be enumerated by the 
thousands, but it is needless. The tool maker should 
bear in mind that a place must be provided for the chips 
made when a tool is cutting, or roughly machined sur 
faces or broken tools (possibly both) must follow. 

3°9 



Welding. 



?=^nS> 




CO 



When it is considered necessary to join two pieces 
of iron, thus making them one, or when it is desirable 
to join the two ends of a bar, thereby making a ring, 
it is accomplished by the process called welding. 

This is of inestimable value as applied to the 
mechanic arts. Not only may iron be welded to iron, 
but steel may be joined to steel by this process. Iron 
may also be joined to steel. 

It is accomplished by heating the metal to a tem- 
perature that makes the surface of a pasty consistency, 
which for soft steel should be a dark white, for iron a 
scintillating white, while for tool steel it should be a 
bright yellow. The formation of a soft pasty layer on 
the surface of the steel is an absolute necessity, in order 
to effect a union of the pieces of metal. This operation 
is assisted by scattering fusible substances on the sur- 
faces to be united, as these protect the work from 
oxidation. These substances are termed fluxes. 
Among those most commonly used are borax, clay, 
potash, soda, sand and sal ammoniac. Ordinary red 
clay, dried and powdered, is an excellent flux for use 
when welding steel, and is one of the cheapest known. 
Borax melted and powdered is called the best of known 
jinxes, but it is so expensive when used in large 

310 



A good flux for welding. 

quantities, that its use is confined to the finest tool 
steels and alloy steels ^ where it is not possible to heat 
the metal as hot as a lower grade of steel. 

A very good flux, whose cost is about one-half that 
of borax, is a mineral barite, or heavy spar. It does 
not fuse as readily as borax, however, but forms an ex- 
cellent covering for the heated surface of the steel. It 

is necessary to fur- 
nish this coating for 
the surface of the 
steel, in order to pre- 
vent oxidation; for 
if any portion is 
oxidized, no matter 
how small the por- 
tion may be, it fur- 
n i s h e s a starting 
point for a break or 
fracture when the piece is under heavy stress. Al- 
though steel may be welded, it is a job to be avoided 
when the welded piece requires hardening. 

Pieces are welded and afterwards hardened which 
remain intact, but it is not advisable unless the weld is 
to be made by a smith skilled in this particular branch 
of the business, and even then it is attended with vary- 
ing results. 

The writer was at one time connected with a 
manufacturing concern who built 50 machines for 
swaging wire. The operation of reducing the diameter 
of the wire was accomplished by dies known as swag- 
ing dies. These were actuated by hammers working 
inside of a large ring. This ring was made of tool 
steel, and in order to save expense, it was considered 




Figure 159. First operation on special 
swaging die. 



311 



Why the piece broke at the weld. 



advisable to take flat steel of the desired size to allow 
for finishing all over, bend in the form of a ring and 
weld the ends. A very skillful smith was given the 
job, but when finished and hardened, the rings broke 
apart at the weld. When broken to examine the grain, 

it was evident that 
the smith had used 
extreme care, yet 
a small portion of 
the welded surface 
was found to be 
oxidized; conse- 
quently, it could 
not unite at that 
place, and a rup- 
ture started from 
that point. 

The method of 
procedure was 
changed, stock 
sufficiently large 
was procured and 
split, as shown in Fig. 159. It was then opened until 
it resembled Fig. 160, and was afterward hammered 
to shape. Before shaping by hammering, however, 
the sharp corners were removed by means of a chisel. 
After machining to the desired size to allow for grind- 
ing, they were hardened as described under Harden- 
ing Large Rings, with the result that not one was 
lost. 

While steel can be welded if great care is used, it 
is very apt to result disastrously if the steel is to be 
hardened. Not only has this been the writer's ex- 

31a 




Figure 160. 



The Derry Collard Co. 
The special swaging die finished. 



Substitute for borax. 

perience. but it seems to be the experience of most 
practical writers on the subject. 



Other Things. 




CO 



Substitute for Borax. 

The following rule for preparing a substitute for 
borax for use in welding high carbon tool steel was 
given the writer several years ago by a blacksmith who 
was considered as an expert in welding steel. He 
claimed that steel could be welded by use of this flux 
at a lower temperature than is required with borax : 

Copperas 2 ounces. 

Common Salt 6 " 

Saltpetre 1 ounce. 

Black Oxide Manganese. 1 ' ' 

Prussiate of Potash 1 " 

All pulverized and mixed with 3 lbs. good welding 
sand. 

Charred Leather. 

While it is possible to purchase charred leather of 
a desirable quality, so much depends on the condition 
of this article that it is always advisable to prepare it 
in the shop where it is used, if possible. 

Use heavy leather, as scraps left when shoe soles 
are punched. Never use light leather, as there is little 



Charred bone for colors. 

goodness in it after charring. The very best article for 
the purpose can be procured from shoe shops. 

To char the leather, fill one or more hardening 
boxes with small pieces, place the cover in position and 
seal with fire-clay. Place in the furnace, leaving it 
just long enough to char sufficiently, so it can be pounded 
fine. Do not expose it to the action of heat long enough 
to destroy the "goodness" of the leather. 

A very satisfactory method is to fill boxes, 9x9x36 
inches, with the leather scraps, sealing the covers as 
described, and placing them in the furnace at night 
after the work has been withdrawn. The remnant of 
fire and the heat of the furnace are sufficient to char the 
leather during the night. As previously stated, do not 
overchar. It should be exposed to the action of heat 
only long enough to break in pieces readily when 
pounded. If smaller boxes are used, it is not advisable 
to leave in the furnace over night. They must be 
watched, and taken out when the leather is charred 
sufficiently. 

Charred Bone for Colors. 

It is necessary, in order to obtain nice colors, that 
the work be polished and absolutely clean ; unpolished 
surfaces will not color. Grease also prevents the ob- 
taining of satisfactory work. 

Pack the work in boxes as previously described, 
except that charred bone is used as packing material. 
When it has run the proper length of time, remove the 
box from the furnace, and dump into a tank of water 
having a jet coming up from the bottom. Better colors 
are obtained if a bath is used having an air pump con- 

3H 



How to char bone. 

nected with the inlet pipe, as illustrated in Fig. 134. 
This shows an easy way of putting in an air pipe, 
connected with inlet water pipe. Soft water in the 
bath gives much better results than hard, although 
very satisfactory results may be obtained with hard 
water if the air pipe is connected as described. 
When hardening for colors by the method under con- 
sideration, it is essential that the box be held very close 
to the top of the water when dumping the work ; the 
box should be inverted quickly, to prevent the air 
striking the work before it reaches the water. If the 
air comes in contact with the metal, the surface as- 
sumes a blue-black color. This is sometimes desirable, 
but not in connection with work packed especially for 
hardening for colors. 

When the work is cold, it may be removed from the 
bath and boiled in clean water. Dry in sawdust, and 
oil the surface either with sperm oil or vaseline. This 
has the effect of making the colors more prominent, 
and it will also keep the steel from tarnishing or rusting. 

To Char the Bone. 

It is sometimes considered desirable to use bone 
rather than leather, and it is thought that the expended 
article would not give the necessary hardness. Yet it 
may be necessary that the articles be tough. This may 
be accomplished by taking raw bone, filling a small 
hardening box with it, placing the cover in position, 
and sealing with fire-clay. When the day's work of 
hardening is taken from the furnace, the box may be 
placed in it, the door shut, the fire extinguished, and 
the box left until morning. If the furnace is one 

315 



How to preserve the bone. 

having light walls, that would lose their heat rapidly, it 
would be found necessary to apply the heat for a time. 
The bone will be found charred when the box is opened. 
Care should be observed that the charring is not over- 
done, however. 

Charred bone may be used as packing material 
either alone or with an equal quantity (in volume) of 
granulated wood charcoal. 

Preserving the Bone. 

When the hardened articles are removed from the 
bath, the water may be drawn off, and the packing ma- 
terial taken out and dried. This may be done by 
placing it on top of the hardening furnace, if that be of 
sufficient size ; if not, it may be spread out thinly and 
allowed to dry. This is the expended bone previously 
mentioned. 

Expended bone may be used for packing certain 
classes of work in, or it may be mixed with an equal 
quantity of granulated raw bone and used the same as 
raw bone. Or it may be used for packing machine 
steel forgings or small articles of cast iron for an- 
nealing. 



316 



High Speed Steels. 



Q^=\ ^=^S> 



CO 

During the past few years various makers have placed 
on the market steels that have revolutionized certain man- 
ufacturing methods. Cutting tools made from these steels 
will retain a cutting edge when extremely high speeds are 
employed; they are also useful when machining stock, 
which is too hard to be machined by ordinary tool steels. 

This grade of steel when adopted by a certain con- 
cern allowed them to reduce the expense of machining 
stock to a degree that made it necessary for their compet- 
itor to use it also, in order to produce his work at a sim- 
ilar cost. As the steel was used it was found that the ordi- 
nary machine was not strong or stiff enough to do the 
work the tools made from it were capable of doing, and 
for this reason many concerns have found it necessary to 
purchase machinery made especially to accommodate these 
tools. 

Extravagant claims are many times made by the 
manufacturers of these tools, claims which it seems were 
better not made ; because the man who attempts to dupli- 
cate them and fails, not only loses faith in them but is 
skeptical regarding other steels when his attention is 
brought to them. 

Failure to realize all that has been claimed for the 
steel may not always be the fault of the steel ; it may come 

317 



Tests that mislead. 

from other causes. First, the operator not being familiar 
with the nature of the steel, may fail to treat it properly 
when making it into cutting tools. Then again the stock 
being machined with the tools may be entirely different in 
composition from that used when making the tests. 

It is an unfortunate fact that most tests are made 
with nice, clean, easily machined, cast iron when that is 
the material used ; or with soft machinery steel, free from 
hard spots. Now every mechanic knows that cast iron 
as it comes from the ordinary foundry to the machine 
shop, is a varying factor ; it may machine easily and we 
may be able to get high speeds even when taking heavy 
cuts, and using coarse feeds ; on the other hand, the com- 
position may be such that the same tool would not stand 
up if we were to run it only half as fast as when machin- 
ing the softer metal. 

At one time while making experiments with one of 
the best known makes of high speed steels, the writer was 
able to run a piece of cast iron in the lathe at a speed of 
ioo feet per minute, the cut was 1-16 inch (removing y% 
inch of stock) and the feed 20 to 1 inch. The tool stood 
up nicely and turned the entire length of the piece with- 
out dulling so that it was noticeable. When we attempted 
to turn another piece from the same pattern which was 
cast from a different mixture it was found impossible to 
retain a cutting edge on the tool if a speed of 45 feet per 
minute was exceeded, retaining, of course, the same depth 
of cut and relative feed. 

Results even more noticeable than those mentioned 
above are experienced when cutting what is familiarly 
known as machinery steel, as unfortunately all grades G\ 
steel between wrought iron and tool steel are classed under 
the head of machinery steel, 

318 



Results are comparative. 

These facts are not mentioned to in any way belittle 
the value of the steel under consideration, but to show the 
reader that he should not get discouraged when he fails 
to get results paralleling those claimed by the makers of 
the steel. The only fair method of judging of the value 
of the steel to the individual is to test in comparison with 
the best tool he can obtain, from tempering steel. 

Because a tool will not stand up on cast iron running 
at ioo feet per minute, as claimed by the maker of the 
steel, is no proof the steel is no good. It might have stood 
all right at 90 feet, and perhaps a tool made from ordinary 
tempering steel might not have stood a speed of 30 feet ; 
in which case the high speed steel was capable of doing 
more than three times the amount of work of the other. 

Many times a difference in cutting speed of only a 
few feet per minute will cause a tool to either stand well, 
or go down. 

There is no general set of instructions that can be 
given for working this steel, as a method that proved 
perfectly satisfactory on one would render another unfit 
for use. For instance, the writer at one time contributed 
an article to one of the mechanical journals on the subject 
of "High Speed Steel," recommending extremely high 
heats when hardening. Shortly after the appearance of 
the article a letter was received from a manufacturer of 
a brand of this steel, saying he had read the article with 
much interest and agreed with everything in it except 
the temperature necessary when hardening, as they had 
found their steel gave best results. when it was hardened 
at a low cherry red heat. 

A trial of a tool which he sent proved it to be equal 
or superior to some that were hardened at the high heat 
mentioned. 

319 



Follow maker's directions. 

To get satisfactory results with any brand the party 
using the steel should follow instructions sent with the 
steel as closely as possible. 

It is evident to the writer from results of his own 
experiments and the experience of others, that when this 
steel is thoroughly understood, results way beyond those 
we are at present getting will be obtained marvelous as 
they seem now. 

While the writer has made extensive experiments 
with the steel under consideration, and has taken advan- 
tage of every opportunity to study its composition, this 
study has been confined to printed statements made by 
those who claim to possess this knowledge. 

Knowing, however, that the successful man in any 
line of business is he who, by studious effort makes him- 
self master of his subject, — what is more natural than 
that the student considering this subject should be anxious 
to know the composition of this steel. 

The following is an abstract of a paper read by Mr. 
J. M. Gledhill before the "Iron and Steel Institute," Octo- 
ber, 1904: 

The high speed steels of the present day are combina- 
tions of iron and carbon with: (1). Tungsten, Molyb- 
denum and Chromium. 

We will consider the influence of each of the elements 
entering into the various compositions. 

Influence of carbon 

A number of tools were made with the carbon per- 
centage varying from 0.4 per cent, to 2.2 per cent, and 
the method of hardening was to heat the steel to the high- 
est possible temperature without destroying the cutting 

320 



Carbon and chromium 

edge, and then rapidly cooling in a strong air blast. By 
this simple method it was found that the greatest cutting 
efficiency is obtained where the carbon ranges from 0.4 
per cent, to 0.9 per cent, and such steels are comparatively 
tough. Higher percentages are not desirable because 
greater difficulty is experienced in forging the steels and 
the tools are inferior. With increasing carbon contents, 
the steel is also very brittle, and has a tendency to break 
with unequal and intermittent cutting. 

Influence of Chromium 

Having found the best carbon content to range from 
0.4 per cent, to 0.9 per cent., the next experiments were 
made to ascertain the influence of chromium varying from 
1.0 per cent, to 6.0 per cent. Steels containing a low 
per centage are very tough and perform excellent work on 
the softer varieties of steel and cast iron, but when tried 
on harder materials the results obtained were not efficient. 
With an increased content of chromium the nature of the 
steel becomes much harder, and greater cutting efficiency 
is obtained on hard materials. It was observed that with 
an increase of chromium there must be a decrease in car- 
bon to obtain the best results, for such percentage of 
chromium. 

Mention may here be made of an interesting experi- 
ment to ascertain what effect would be produced in a rapid 
steel by substituting vanadium for chromium. The 
amount of vanadium present was 2.0 per cent. The steel 
readily forged and worked very tough and was hardened 
by heating to a white heat and cooling in an air blast. This 
tool when tried on medium steel stood well, but not better 
than the steel with the much cheaper element of chromium 
in it. 

321 



Other alloys. 

Influence of Tungsten 

This important element is contained in by far the 
greater number of the present high speed steels in use. 
A number of experiments were made with the tungsten 
content ranging from 9.0 per cent, to 27.0 per cent. From 
9.0 per cent, to 16.0 per cent, the nature of the steel be- 
comes very brittle, but at the same time the cutting effi- 
ciency is greatly increased and about 16.0 per cent, ap- 
peared to be the limit, as no better results were obtained by 
increasing the tungsten beyond this figure. Between 18.0 
per cent, and 27.0 per cent, it was found that the nature 
of the steel altered somewhat and that instead of being 
brittle it became softer and tougher, and whilst such 
tools have the property of cutting very cleanly they do not 
stand up so well. 

Influence of Polybdenum 

The influence of this element is still under investiga- 
tion and our experiments with it have produced excellent 
results, and is was found that where a large percentage 
of tungsten is necessary to make a good rapid steel, a con- 
siderable less percentage of molybdenum will suffice. A 
peculiarity of these molybdenum steels is that in order to 
obtain the greatest efficiency they do not require such 
a high temperature in hardening as do the tungsten steels, 
and if the temperature is increased above 1,800 degrees F. 
the tools are inferior and the life shortened. 

Influence of Tungsten with Molybdenum 

It was found that the presence of from 0.5 per cent, 
to 3.0 per cent, molybdenum in a high tungsten steel 
slightly increased the cutting efficiency, but the advantage 

322 



Influence of silicon. 

gained is altogether out of proportion to the cost of the 
added molybdenum. 

Influence of Silicon 

A number of rapid steels were made with silicon con- 
tent varying from a trace up to 4.0 per cent. Silicon sen- 
sibly hardens such steels, and the cutting efficiency on hard 
materials is increased by additions up to 3.0 per cent. By 
increasing the silicon above 3.0 per cent., however, the 
cutting efficiency begins to decline. Various experiments 
were made with other metals as alloys, but the results 
obtained were not sufficiently good by comparison with 
the above to call for comment. 

Analysis of one of the best qualities of rapid steels pro- 
duced by Mr. Gledhill's firm (Armstrong Whitworth 
Co.), is as follows: "A. W." steel Carbon 0.55 per cent; 
Chromium, 3.5 per cent. ; Tungsten, 13.5 per cent. 

Tools made from high speed steels in order to give 
best results when heavy cuts and coarse feeds are em- 
ployed, should be made of a form that insures strength 
and rigidity and must cut freely. Many times tools are 
made having very little clearance on the portion that pene- 
trates the stock as shown at A Fig. 161 ; now if a coarse 
feed is employed it is apparent that such a tool will bear on 
the stock below the cutting edge, as a consequence the tool 
cannot cut as rapidly as the lathe carriage is traveling 
and it must turn in the tool post. If the operator is not 
attentive he will not observe the trouble, and in order to 
securely fasten the tool he will tighten the binding screw 
so tightly that he either breaks the tool post binding screw 
or he succeeds in binding the tool so it cannot turn, and 
the feed belt slips, or the pressure against the stock actu- 

323 



Shapes of high speed steel tools. 

ally crowds off a portion of the cutting edge of the tool. 
It is necessary when taking heavy cuts with coarse feeds 
to give a tool sufficient clearance as shown at B. Fig. 161, 
so no part of the tool below the cutting portion will touch. 
Too much clearance, of course, weakens the tool and is to 
be avoided. 

While slender side tools, diamond point, and similar 
tools, give excellent results when made from high speed 




Tne Derry\Collard Company 
Figure 161. Side clearance of tools. 

steel, the more noticeable results are obtained when heavy 
cuts are taken. To accomplish this it is necessary to use 
tools which are stubbed and strong and having as little 
top rake as is consistent with fairly easy cutting. For 
this reason tools having portions standing out from the 
shank (as a diamond point tool) are not generally satis- 
factory. A tool made as shown in Fig. 162, will be found 
to give best results when heavy cuts are taken. 

Many tools are on the market which use separable 
cutters. These cutters may be of high speed steel which 
can be purchased in any of the common forms and sizes. 
The steel as it comes in the bar is glass hard unless it is 
ordered annealed. However, if best results are desired, 
it is advisable to harden it before using even when it is not 
necessary to forge it to shape. 

324 



To anneal or not to anneal. 

If it is desirable to have the steel in the annealed con- 
dition, better results are obtained, generally speaking, if it 
is purchased in this condition, than if annealed in a shop 
that does not have the necessary facilities for maintaining 
a heat for a considerable length of time. 

There is a difference of opinion among mechanics 
using this steel as to effect of annealing on the hardened 



Figure 162. A good tool for heavy cuts. 

tool, some claiming that tools made from steel that has 
been annealed will not stand as much as if made from 
stock that had not been annealed, while others claim best 
results from steel that has been annealed. The writer in 
his experiments has failed to notice any material differ- 
ence, provided due care had. been experienced in the var- 
ious operations. 

The writer saw not long ago some drills made from 
bars of a well-known brand of this steel which was not 
annealed. The steel was flatted, then twisted to shape 
while hot. After being hardened they were ground to 
size. They certainly stood up much better when tested 
than drills made from other brands whose grooves were 
milled from annealed bars. Whether the difference was 
due to the fact that one steel was annealed and the other 
not, or to the difference in the method of making, the 
writer is not ready to say. This much he does know ; the 

325 



Annealing high speed steel. 

drills referred to were heated to a high heat and quenched 
in luke warm brine, while no one knew how the others 
were hardened. It would not be safe to dip some brands 
of this steel in brine, while others work nicely when tools 
of certain shapes are hardened in it. 

When making certain tools, as taps, milling machine 
cutters, dies of various kinds and similar tools it is neces- 
sary to anneal this steel in order that it may be worked 
to shape, and unless it is properly annealed it is very try- 
ing, as well as extremely costly, to attempt to machine it 
to form. 

The writer has made exhaustive experiments in the 
annealing of this steel and has found that some of the 
methods advocated, work in a manner that is anything 
but satisfactory. It is necessary to pack the steel in the 
annealing box with some substance that will exclude the 
air as much as possible. For this reason charcoal has not 
worked as well as other substances. Lime, if used as a 
packing material, insures a good anneal if the process is 
carried on properly; but appears to leave a heavy hard 
scale on the outside. Some claim good results from a mix- 
ture of lime and charcoal ; this the writer has not tried be- 
cause excellent results were obtained by packing the steel 
in dry clay in an annealing box, the cover being put in 
place and sealed, the box placed in the furnace and the 
steel heated to a yellow. It was allowed to cool as slowly 
as possible. The exact temperature necessary to heat the 
steel, in order to get satisfactory results depends some- 
what on the steel used and also on the size of the piece. 
Smaller pieces do not require quite so much heat as larger 
ones, neither should they be subjected to heat for as great 
a length of time. 

The following method is practised in a shop that an- 
326 



Annealing materials. 

neals over a ton of high speed steel per clay. This steel is 
of several makes and the method seems to apply equally 
well to any of them, and is as follows : The steel is 
packed in long pipes with a mixture of charcoal, lime, 
and cast iron chips in equal quanities. The steel is placed 
in the furnace in the morning and subjected to heat all 
day the temperature which as gauged by a pyrometer, is 
between 1,600 and 1,700 degrees. The steel is allowed 
to remain in the furnace all night and cool off with it. In 
the morning the tubes containing the steel are removed 
from the furnace, covered with hot ashes and allowed to 
cool as slowly as possible. 

While this method appears to give excellent results, 
I have obtained best success with fire clay as a packing 
material ; either material may be used over and over with 
good results. 

The idea prevails among some mechanics that this 
steel after being hardened cannot be annealed and then 
hardened again. While I have never experimented along 
these lines with all the different makes I have with sever- 
al of them, and found no trouble when the tool was re- 
peatedly annealed and hardened. I could not detect any 
difference in the cutting qualities of the tool after it had 
been hardened four or five times. 

One objection raised against this steel for tools to be 
used in the lathe or planer, where the tool was held in a 
tool post and thereby subjected to the breaking strain in- 
cident to the manner which it was held, is, that the steel 
broke in the tool post when heavy cuts were being taken. 
This trouble may be avoided by annealing the bar, or cut- 
ting it to proper lengths and annealing, after which the 
tool may be forged and hardened. It is not considered 
good practice to attempt to harden tools made from this 

327 



Handle according to conditions. 

steel any where except on the cutting end, thus leaving 
the portion in the tool post sufficiently tough to resist the 
breaking action of the screw. 

When annealing the steel for the purpose just men- 
tioned above, it is not necessary to be as thorough as when 
it is to be worked with cutting tools, and it may be ac- 
complished by heating the steel to a low yellow heat and 
burying in red hot ashes (or lime which has been thor- 
oughly heated before the steel is placed in it), it is neces- 
sary to thoroughly protect it from the chilling effects of 
the air, or any material which is cold or damp. 

In order to get satisfactory results in the hardened 
tool it is necessary after forging, to reheat the tool to a 
full red and allow it to cool off, thus relieving the strains 
incident to forging; when cool it may be reheated and 
hardened. 

While the amount of heat necessary to insure best 
results when hardened steels of different makes cannot be 
stated arbitrarily, it is claimed for most of them that a full 
red heat should be employed when forging. However 
some makers claim best results for their steel if it is heated 
to a full yellow (above 1,850 degrees), at which tempera- 
ture it is soft and easily worked. The forging proceeds 
until the temperature lowers to a good red, say 1,500 
degrees, when work on the piece should cease and the steel 
reheated before forging is removed. It is, however, best 
to get instructions from makers of the steel, as to the tem- 
perature that insures best results, before doing any work 
on it. 

In case of the smith who carefully observes the ac- 
tion of heat on steel I claim that he can, in a short time, 
find out more about the proper heat and method of work- 
ing a given brand of this steel in order that the tools may 

328 



How to work high speed steels. 

give satisfaction in the shop whose condition he under- 
stands, than it is possible for him to learn from any in- 
structions the maker can furnish, because these instruc- 
tions must of necessity be general and cannot apply to the 
varying conditions found in the individual shop. The 
careful smith will soon find out for himself at what heat 
the steel works best under the hammer. The heat should 
be one that allows the steel to work nicely. While the 
maker of some of these steels claim good results when it 
is placed in the hands of men who are not specially skill- 
ful in the manipulation of steel, I think I am safe in say- 
ing that when forging most brands, it is necessary to exer- 
cise greater caution than when forging high carbon steels, 
and every smith knows they are extremely sensitive. 

If the steel is hammered when it is not hot enough 
the grain is fractured. If large pieces are being worked, 
the blows should be sufficiently heavy to cause the steel to 
flow as uniformly as possible; heavy blows with a heavy 
hammer should not be given a light section. The forging 
heat must be uniform, that is, the piece must be as nearly 
as possible of the same temperature at the center as the 
surface. 

Blacksmiths are sometimes careless when working 
these steels, thinking that because high heats when hard- 
ening are essential to good results, any heat will do for 
forging. This is a great mistake as the steel is extremely 
sensitive but requires high heats when hardening to give 
it the desired cutting qualities. 

A common mistake and one that has proved very 
costly to many concerns, consists in changing from a steel 
that has been giving satisfactory results for another 
whose only recommendation is that the representative 
shows testimonials from parties who have used it and 

329 



About following instructions. 

claim results way beyond what is being received from the 
brand they are using. In all probability the other parties 
are machining a stock entirely different in composition and 
as a consequence are able to get more work out of the 
tools. 

The writer would not be understood as saying we 
should always "let well enough alone" and continue to use 
an inferior article while his competitor was getting the 
best and as a consequence is leaving him way in the rear. 
But many times parties have discarded one steel and 
adopted another which was no better and in doing so they 
have adopted a steel that required different treatment from 
the one they were using at first. The smith not realizing 
this fails to treat it properly and the results are not as 
satisfactory as with the first. 

If steels of different makes are used they should be 
distinctly marked and the smith should be given explicit 
instructions for working each. Generally speaking, how- 
ever, it is poor policy to have several makes of this steel 
around at the same time. 

The operator should follow instructions accompany- 
ing the steel to the letter, unless experience has convinced 
him and all concerned that some other method of treat- 
ment is better adapted to their needs. 

However the instructions given do not always in- 
struct, and sometimes the men sent out by the steel con- 
cerns as demonstrators know less about the steel they rep-, 
resent than the smith whom they are supposed to teach. 
This does not necessarily prove that the steel is of no 
value. 

The smiths who are the most successful in handling 
these steels are the ones who are ever on the lookout for 
knowledge, and learn all they possibly can of its nature, 

330 



Heating for forging. 

and the treatment best adapted to the needs of the shop 
they are in. 

I think most blacksmiths who have had an extensive 
experience working high speed steels prefer a fire of coke 
when heating for forging. 

Heating for Forging. 

We have been taught from the time we first hardened 
a piece of steel that high heats were to be avoided, that 
the lower the heat the more serviceable the tool, provided, 
of course, it was sufficiently high to accomplish what we 
desired. Now a steel is given us which requires a full 
white heat in order to give it a condition that insures doing 
what we expect of it. That is, most makes of this steel 
require the high heat mentioned. If the tools to be hard- 
ened are of a form that are not injured by scaling they 
may be heated in an open fire in an ordinary blacksmith's 
forge. If, however, taps, reamers, milling machine cut- 
ters, or any form which would be injured by scaling are to 
be hardened, they must be heated in a gas or other furn- 
ace especially made for high heats, or in a crucible of lead 
heated to the proper temperature. The lead being at a 
very high temperature the surface has a tendency to oxi- 
dize very rapidly; this can be prevented somewhat by 
placing powdered charcoal on the top, which must, of 
course, be renewed frequently. 

A very satisfactory method of heating specially 
formed tools of high speed steel, such as taps, dies, milling 
cutters, reamers and similar tools, is a muffle furnace of 
special design, heated by oil or gas. This furnace has two 
chambers one above the other. The lower chamber may 
be heated to a temperature of 2,200 degrees Fahr., and 

331 



Hardening apparatus. 

the temperature maintained uniformly, while the upper 
chamber is not heated nearly as hot. The tools may be 
slowly heated by placing on top of the furnace in a tem- 
perature that does away with the tendency to crack when 
they are subjected to a higher heat. While in the upper 
chamber they can be brought to a red heat. It is now safe 
to place them in the lower chamber and allow them to re- 
main until they are of the proper temperature for hard- 
ening. 

When electric current is available an excellent method 
of heating may be had that is rapid, reliable and easily 
controlled. The description of this method is taken from 




Figure 163 



Apparatus for hardening tools electrically in a bath of 
potassium carbonate. 



the abstract of paper read by Mr. J. M. Gledhill previously 
referred to. A brief description of this kind of heating 
may be of interest. 

One method adopted for electrically heating the 
points of tools, and the arrangement of apparatus is shown 
in accompanying cut, Fig. 163. It consists of a cast-iron 

332 



When a forge must be used. 

tank of suitable dimensions, containing a strong solution 
of potassium carbonate, together with a dynamo, the posi- 
tive cable from which is connected to the metal clip hold 
ing the tool to be heated, while the negative cable is con > 
nected direct on the tank. The tool to be hardened is held 
in a suitable clip to insure good contact. Proceeding to 
harden the tool the action is as follows : 

The current is first switched on and then the tool is 
gently lowered into the solution to such a depth as is re- 
quired to harden it. The act of dipping the tool into the 
alkaline solution completes the electric circuit and at once 
sets up intense heat on the immersed part. When it is 
seen that the tool is sufficiently heated the current is in- 
stantly switched off, and the solution then serves to rapid- 
ly chill and harden the point of the tool, so that no air 
blast is necessary. 

If it is necessary to heat in an ordinary forge when 
hardening lathe, planer and similar tools, the point only 
of which needs hardening, a good large fire of well coked 
coal may be used, making sure that the fire is large enough 
so that no air from the blast inlet will strike the heated 
portion. When the desired heat has been obtained the tool 
is then held in a strong air blast of generous proportions. 
Best results are obtained if the point of the tool is held 
several inches away from the nozzle of the blast pipe. If 
an air blast is not available, dip the point of the tool in oil, 
raw linseed, cotton seed oil, or almost any fish oil will 
answer. * 

After hardening the tool may be ground to shape, and 
it is ready for use, unless projecting portions or light sec- 
tions necessitate drawing the temper to insure sufficient 
strength. The object attained in drawing the temper is 
that the brittleness is reduced so the tool will not break 

333 



Heating for hardening. 

when subjected to shock and strain incident to cutting. 
When the temper has been drawn the desired amount, lay 
the tool to one side and allow it to cool slowly where no 
current of air can strike it. Do not quench it when the 
proper temperature is reached for while it is safe to plunge 
certain shapes of tools made from this steel in hot water 
when at a high heat, it is not safe to quench them at 
tempering heats. 

If such tools as milling machine cutters, taps, reamers 
and similar tools are to be heated for hardening, it is nec- 
essary to remove them from the oxydizing action of the 
air when at the high heat. To accomplish this they may 
be heated in specially constructed furnaces as previously 
described, or in a crucible of lead. The furnace described 
is so designed that there are three steps in the heating 
operation ; first the cold cutter is placed on top and heated 
somewhat, so it is possible to subject it to a red heat with- 
out cracking it as would be the case if the cold steel were 
subjected to the red heat. After becoming heated some- 
what it is placed in the upper chamber where it is gradual- 
ly heated to a full red heat ; it is then placed in the lower 
chamber and heated to the proper temperature to insure 
desired results. 

If the furnace used has but one chamber it is neces- 
sary to heat the tool to a red in an open fire or where it 
may be heated slowly ; it may then be placed in the furnace 
and given the desired temperature. 

Now, while a crucible of lead is many times used to 
heat tools made from high speed steels for hardening, its 
use as a permanent means of heating is hardly to be ad- 
vocated as the lead oxidizes very rapidly and the fumes 
are poisonous. For the same reason that it would not do 
to place a cold tool in the chamber of the furnace, it is nec- 

334 



Care in hardening. 

essary to heat articles red hot before plunging in lead 
heated to a white heat. If the tool was immersed when 
cold into lead heated to the temperature mentioned it 
would spring or crack from the sudden expansion of the 
outer surface of the steel. The tool should be allowed to 
remain in the lead just long enough to insure a uniform 
heat of the proper temperature. 

If comparatively large tools are to be heated in the 
lead, the crucible should be of generous proportions, or 
the contents will be cooled so much by immersion of the 
steel that the temperature will be lowered to a point that 
will necessitate reheating to bring it to the high heat 
required. 

At times the operator is deceived as to the proper heat 
by attempting to get heats that insure a hardened surface 
that cannot be touched with a fire. The steel may be so 
hard, a file will have no impression on it and yet fail to 
give satisfactory results. Again, tools which are hard- 
ened at the temperature necessary to give this, may leave 
the temperature drawn until they file readily and still 
stand up nicely when tested at high speeds and heavy cuts. 
The intense heat is necessary to bring about certain chem- 
ical changes necessary to give desired results. 

When the tool is heated to the required temperature 
it may be plunged in a bath of raw linseed, cotton-seed, or 
fish oil, and allowed to remain until cool. If it is an end 
mill, excellent results are many times obtained by quench- 
ing in boiling water, or hot brine. It is necessary to re- 
member, however, that only the portion heated to a white 
may be put in water, or the part which is not so hot is 
liable to crack. 

The writer's experience in hardening taps does not 
warrant his advising the use of lead as a heating medium 

335 



Drawing the temper. 

for them ; and he has seen the representatives of steel con- 
cerns selling this steel have repeated poor success when 
trying it. Probably the most satisfactory method is to 
heat in specially prepared furnaces, but such furnaces are 
not always available, and excellent results may be obtained 
by placing the tap in a piece of gas pipe closed at one end, 
a quantity of finely broken charcoal or coke (the writer 
prefers coke) may be placed in the tube and the remaining 
end sealed. The tube may now be heated to the desired 
temperature, the top removed and plunged in oil. It will 
be necessary to draw the temper of tools having slender 
teeth, this drawing is nicely done in heated sand. The 
amount necessary to draw the temper will depend on the 
use to which it is to be placed, it may be a straw, brown, 
or blue color, or in cases requiring freedom from brittle- 
ness the tool may be heated until a dull red shows when 
it is held in a shaded place, as in a barrel or keg. 

When pieces have been heated for tempering, place 
them where no dampness or current of air can strike them, 
and allow them to cool off. 

In the case of taps it will be found advisable to heat 
the shanks red hot in red hot lead, then place the shank 
in lime to cool off as slowly as possible ; this may be done 
after drawing the temper of the cutting end. 

Some mechanics using this steel, object to drawing 
temper, saying it should be as hard as it can be made. 
However, if we attain to anything like the speeds claimed 
for the steel, it is very quickly heated to a temperature 
even higher than the temper heats mentioned, so it is ob- 
vious that drawing temper for toughness can not serious- 
ly detract from its staying qualities and it is certainly nec- 
essary when parts that are weak are to be subjected to 
great strain. 

336 



Speeds and feeds. 

Experience has convinced the writer that it is a 
mistake, generally speaking, to grind lathe, planer and 
similar tools on a wet emery wheel, as it requires consider- 
able pressure of the tool on the wheel to insure its cutting, 
this pressure is, of course, productive of heat, the water 
striking the heated steel causes it to crack ; especially are 
the above results noticeable if the grinding is done by men 
not extremely careful. 

Best results follow grinding on a free cutting dry 
wheel, after which it may be finished on a free cutting 
grind stone. 

Speeds and Feeds, 

As previously stated the speed at which these steels 
can be used with satisfactory results depends in a great 
measure on the condition of the stock being machined. 
Many times the depth of chip and the rate of feed are en- 
tirely overlooked and as a consequence less stock is re- 
moved than if the machine was run somewhat slower and 
heavier cuts and coarser feeds used. 

It is necessary, however, in order to have something 
tangible, that we have before us results of tests made with 
stock of various kinds and as the writer has never kept a 
record of results obtained in his experiments it has seemed 
wise to give results claimed by the makers of certain 
brands of this steel. The reader need not be discouraged 
if he is not able to duplicate the results given in the table, 
and yet under certain conditions he may be able to do even 
better. 

One maker claims, .that when turning bars of hard 
steel the stock was run at a rate of 160 feet per minute, 

337 



High cutting speeds. 

the depth of cut Y^ inch, the feed 1-32 inch, the amount 
of stock removed in a day of 10 hours being about 2,500 
pounds, the cutting tool being ground but once a day. 

Another maker claims that twist drills made from 
their steel would stand from two to four times the speed 
of the best carbon steel, and even at the high speed would 
drill from 6 to 25 times as many holes before it required 
grinding. 

He also claimed that taps made from their steel would 
stand three or four times the speed of regular tool steel 
taps, and stood up 40 to 50 times as long. 

Reamers from the same steel it is claimed, were run 
at twice the speed of those made from ordinary carbon 
steel and showed an efficiency of 15 to 1. 

Milling machine cutters made from another make of 
this steel were run at a rate of 150 feet per minute on 
mild open hearth steel, as compared to 28 feet per minute 
with a similar cutter made from regular tool steel. 

Experiments in cutting cast iron in the lathe showed 
that a speed of from two to four times that possible when 
tools made from carbon steels, was used. 

Hardening and Tempering Rock Drills 

Drills used in drilling rock are used under vastly dif- 
fering conditions, and are not all treated alike. The suc- 
cess of a drill depends in a large measure on the steel 
used, in its construction and in the treatment it receives 
when it is forged. As the sharpener has constant prac- 
tice and his whole time is devoted to this one line of work 
he becomes very skillful and, while he works quite rapidly, 
he is extremely careful when heating and forging. 

The shape of the drill has nearly as much to do with 

33 8 



Hardening rock drills. 

ability to stand up as the method employed in hardening, 
so the sharpener should find the shape that gives best re- 
sults and then stick to it as closely as possible. 

The sharpening should be done at low heats and 
blows should be lighter as the steel cools, to prevent 
crushing the grain. 

The heat for hardening should be the refining heat 
for the particular steel being used. 

A bath of brine made by dissolving all the salt it will 
take in a tank or barrel of rain-water, is the one common- 
ly used, although some sharpeners add other ingredients. 

The hardening generally extends from I inch to i^ 
inches up from the point, the steel being heated higher up 
contains sufficient heat to draw the temper the desired 
amount. 

The treatment of the steel during forging and hard- 
ening has a great deal to do with the amount it is "let 
down" in tempering. If the heats were low the steel will 
be strong and the temper may be left high ; if the heats 
were high the steel will be brittle and the temper must 
be drawn considerable. We will assume, however, that 
the heats have been carefully gauged for both forging and 
hardening. 

For most steels that have come under the observation 
of the writer, the temper should be drawn to the faintest 
color visible, that is, when the temper color commences to 
show, the drill should be checked in oil ; under certain 
conditions, however, the temper is drawn to a light straw 
color. 



339 



High Carbon Steel 




Hardening High Carbon Steel; Tungsten Steel; 
Recalescence ; Phenomena of Recalescence 
and Reheating; Heat Gauges; Quenching; 
Annealing; Temperature for Hardening; 
Tempering High Carbon Steel; Colors for 
Tempering. 

All varieties or grades of carbon steel are altered by 
being suddenly cooled or "quenched" when heated and 
this alteration varies greatly according to the heat at 
which the steel is cooled, the quality and composition of 
the material, the quenching medium used and other 
causes. In the high carbon steels this effect is particu- 
larly noticeable and such steels, when so treated, become 
hard, brittle, or tough according to the exact heat treat- 
ment and manner of quenching given. The change in 
the steel takes place during a very short range of tem- 
perature and the more rapidly the cooling occurs through- 
out that range the harder the steel will become. This 
particular range of temperature for hardening is known 
as the "critical range" or "point of recalescence" and 
varies with the carbon percentage in the steel. This 
point of recalescence indicates the proper quenching tem- 
perature and most complex and exhaustive tests have 

34o 



Recalescence. 

been carried on to ascertain the exact points of recales- 
cence best adapted to various steels and various purposes. 

Quenching the steel at the lowest temperature at 
which hardening will occur produces the toughest tools, 
whereas, if the same tool be heated to the utmost tem- 
perature of the critical range and then cooled suddenly 
great hardness but very brittle results will be obtained. 
Connected with this peculiar point of recalescence are 
numerous physical and chemical phenomena which are 
difficult for the layman to understand and cannot be fully 
dealt with or explained in a work of the present scope 
but a few words of explanation and some data of experi- 
ments that have been carried on will prove an aid in 
more thoroughly understanding and appreciating the 
subject. High carbon steels contain a very complex 
material commonly called "Martensite," which in slow 
cooling is altered to "Pearlite" and produces a softness 
or lack of temper in the steel. When rapidly cooled this 
is again transformed to the so-called "Hardenite," which 
produces extreme hardness and brittleness. 

Oddly enough steel does not cool steadily and evenly, 
but at about 1237 degrees (F.) the cooling ceases and 
the temperature even rises a trifle. The point of recal- 
escence having passed the cooling continues, but as radia- 
tion is continually drawing heat from the steel during 
this period, it is obvious that the temporary retardation 
of cooling must be brought about through some alteration 
within the material itself. This alteration, which in large 
masses makes the steel glow more brightly, marks the 
point at which the steel should be quenched to obtain 
certain results. In heating soft steels for hardening the 
point of recalescence is reached when heat is absorbed 
without raising the temperature brought about by the 

34i 



Magnet gauges. 

transformation of the Pearlite to Martensite or exactly 
the reversal of the other process. When tempered, how- 
ever, a portion of the Hardenite or Martensite in the 
hard steel is transformed into Pearlite by means of "bak- 
ing" or gentle heating until the steel contains both Mar- 
tensite or Hardenite and Pearlite. A most remarkable 
feature of these properties of steel is the fact that at the 




Fig. 164. Magnets for heat gauges. 



exact point of recalescence the steel loses its magnetic 
property and can neither attract nor be attracted by this 
force. This phenomenon has resulted in very accurate 
gauges for testing the heat of steel and ascertaining the 
exact point of recalescence. Several forms of these mag- 
netic gauges are made, some of which are shown in 
Fig. 164. 

The simplest form for small tools and similar ob- 
jects consists of a magnet provided with arms of any 

342 



Hardening carbon steel. 

desired shape. The tool to be heated is then attached 
to these arms by magnetic attraction and heated in a 
blow-pipe flame over a quenching bath. When the criti- 
cal point of heating is obtained the steel loses its mag- 
netic properties and drops from the magnet to the bath 
below. A very simple manner of ascertaining the critical 
point where magnetic gauges are unavailable is to test 
the magnetism of the heated steel by placing it near a 
small compass. When the needle ceases to vary by its 
proximity to the steel the proper point of recalescence is 
determined. Other adaptations of this magnetic phe- 
nomenon are developed on large scales in the magnetic 
furnaces wherein the steel is so arranged that upon the 
loss of its magnetic force a bell rings, or colored lights 
appear, thus indicating that the point of recalescence is 
reached. 

Extensive experiments carried on in this connection 
give some most interesting and remarkable tables, figures 
and results, which in a simplified form are interesting 
and of value to all those handling high carbon and low 
tungsten steels. In these experiments the materials used 
were "Low-tungsten" steel and carbon steel of about 
1. 1 6 per cent carbon. These experiments showed that 
nearly the entire hardening change occurred within a 
margin of about 9 degrees F., and that the difference 
between steel quenched from 1355 degrees F. and 1364 
was so great that it was difficult to believe that the hard 
bar and soft bar only differed by being treated to 5 de- 
grees variation in heat. In its fractures these carbon 
and tungsten steels also exhibited wonderful properties, 
for while ordinary tool steel may be heated to 180 degrees 
beyond its hardening point without a noticeable differ- 
ence in fracture, yet the steels experimented upon dis- 

343 



Temperature changes. 

played a marked difference when the heat varied but 54 
degrees. 

In heating these steels it was determined that the 
temperature did not rise regularly but for several min- 
utes remained stationary while in cooling a long period 
ensued at which the temperature remained constant. 
These peculiarities were recorded on a Callender recorder 
as illustrated in Fig. 165. It is evident from these ob- 
servations that during these stationary periods of tem- 
perature the heat that entered the steel was utilized in 
effecting the hardening process. When the steel was 
cooled slowly the temperature fell very regularly until 
at 13 15 F. ; steel at this temperature was still radiating 
great heat, but, nevertheless, the temperature ceased to 
fall and in fact it actually rose 5 degrees. During this 
halt the steel changed from its hard state and assumed 




Fig. 165. Recalescence curves of low-tungsten and high-carbon steels. 



an annealed condition, the heat that had previously been 
absorbed in producing hardening being released and 
maintaining the temperature. This peculiar phenomenon 
is analogous to the melting of ice for we can understand 
that if ice at 20 degrees, or below, is heated to a tem- 
perature of 60, or more, there would be a long period at 

344 



Experiments with temperature changes. 

the temperature of 32 degrees, during which the tempera- 
ture would remain stationary, as all the heat applied 
would be expended in melting the ice and transforming it 
to water instead of increasing the temperature, and that 
if the process were reversed there would be a time when 
the freezing point was reached, when the latent heat 
necessary to retain the water in a liquid state would be 
realized as the ice formed, but when thoroughly con- 
gealed the temperature would again fall. 

The result of the experiments and heating and cool- 
ing curves obtained in the experiments mentioned was 
to prove that there is a place at which an absorption of 
heat takes place during heating and another where an 
emission of heat or recalescence occurs during cooling 
and that these two points do not occur at the same tem- 
perature and are not directly related to one another. 

This demonstrated that annealed steel will not 
change into a higher state until a certain temperature is 
reached and held for some time but that as soon as the 
change has taken place the higher state is sufficiently 
stable to overcome alteration back to its former state 
until there is a decided variation, or in other words, if 
the steel is brought to the proper hardening temperature, 
merely cooling it too much below the temperature will 
not undo the work accomplished by heating it. This 
valuable discovery has a most important bearing on hard- 
ening treatments, for if a tool has been properly heated 
for hardening it may remain for some time at a lower 
temperature and still be perfectly hardened when 
quenched, but, nevertheless, continued exposure to the 
high temperatures, after the proper hardening point is 
reached, will result in softening as may readily be proved 
by treating two bars of steel, allowing one to reach just 

345 



Preparations for hardening. 

the critical point before quenching while allowing the 
other to remain "soaking" for some time before it is 
quenched. Moreover, if the steel is overheated and then 
quenched it will be even softer than if "soaked" for a 
long period at the proper temperature. 

Having thus entered more or less into the little 
known and less understood question of the phenomenon 
of recalescence we will take up the matter of preparing 
high carbon and similar steels for hardening. 

Steel forgings do not pass direct from forge to hard- 
ening room as they are at first coated with a thin film of 
oxide which cannot be hardened and must be removed 
by grinding with a wet grindstone. If a carborundum 
or emery wheel is used for this purpose glazing may 
result which is in reality a burning of the surface, ren- 
dering the spots so affected incapable of hardening and 
resulting in uneven work and poor tools. 

Work that has been machined before hardening 
must be carefully inspected before treating, as sharp 
angles, scratches and other faults often develop into 
serious flaws or cracks in the heating and quenching 
process. 

It pays to be most careful in this regard as it is far 
better to refinish or reforge an article before hardening 
rather than expend the time, labor and money on careful 
hardening only to have a faulty object in the end. 

The source of heating for hardening may be either 
a common forge with a coke fire, a reverberatory or 
muffle furnace, a salt-bath furnace or special hardening 
ovens or furnaces. Small articles may be heated in an 
iron box or pipes and excellent results may be obtained 
by heating small tools in a piece of ordinary gas pipe 
plugged at the ends and heated in a common furnace or 

346 



Baths for quenching. 

forge. Very small articles may be heated by blow-pipe 
or even by placing them on another piece of heated steel 
and testing for the point of recalescence by a magnetic 
gauge. The main object is to produce a bright, cherry 
red heat at the proper temperature without allowing air 
to reach the heated surface and thus oxidize the steel and 
also to avoid sulphur in the fuel ; for this reason coke is 
better than coal and charcoal is better than coke, while 
oil or gas is superior to either, and electrical heat is best 
of all. 

The substance used as a bath for quenching, or rap- 
idly cooling, the steel varies with different operators and 
different steels as well as according to the grade of hard- 
ness or temper desired. Water, oil, brine, mercury, 
melted lead, are used extensively. The whole object of 
the quenching medium is to cool off the hot steel as 
rapidly as consistent with safety, and oil and water are 
most generally used ; a very cold medium is not desirable, 
as cracks often result, and as the melting point of lead is 
far below the hardening point of carbon steel and as that 
metal is an excellent heat conductor, the lead bath is fre- 
quently used. Oil is used where extreme brittleness is 
undesirable, while mercury is used where extreme hard- 
ness is required. Care must be taken to immerse the 
entire parts to be hardened at practically the same instant 
for otherwise distortion and unevenness will result. If 
properly hardened the steel when first taken from the 
bath will have a mottled, whitish appearance and if not 
mottled the steel is not properly hardened. If hard a 
file will slip over it, whereas if soft, it will cut. If soft 
it shows that either the steel was not heated sufficiently 
or else that it was cooled too slowly during the period 
of recalescence. 

347 



Table of temperatures 

Table of Temperatures for hardening high carbon 
steel : 

Approx. temperature Color in full 

— degrees F. Daylight. 

430 Pale yellow 

450 Straw 

470 Dark straw 

500 Brown yellow 

53° Light purple 

550 Purple-blue 

560 Blue 

580 Polish blue 

600 Deep blue 

750 Bright red 

880 Red, dull 

980 Nascent red 

1,080 Red 

1,290 Dark red 

1,470 Nascent cherry 

1 ,660 Cherry 

1,830 Bright cherry 

2,010 Dull orange 

2,100 Light orange 

2,190 Lemon 

2,280 Light straw 

2,400 White 

2,550 Brilliant white 

2,730 Dazzling white 

343 



Tempering high carbon steel. 

Tempering high carbon steel is for the purpose of 
reducing the brittleness produced by hardening and it is 
accomplished by heating or "baking'' the hardened steel 
to a moderate temperature the degree of which deter- 
mines the temper and not the method of quenching as 
commonly supposed. The lower the temperature to 
which it is subjected the less will be the loss of hardness 
by tempering, and as a rule the proper temperature to 
produce a given temper is recognized by the color that 
is assumed by the oxidized film upon the surface. The 
color deepens as the temperature rises, and while this 
method is far from perfect, it is very simple and widely 
used, and a man accustomed to the work can judge 
wonderfully well just where to stop by the color alone. 

For a beginner this process is very difficult, for the 
color changes with time, as well as temperature, and a 
dark blue may show by heating an object to 652 F. in 
one minute or by keeping it at 392 for four minutes, and 
thus practice, care and judgment are essential to this 
work. 

By heating in a bath of oil, lead, salts, etc., or in an 
electrical or special oven the exact temperature may be 
ascertained, but even then experience and judgment is 
very necessary to insure even and accurate tempering. 
The following table indicates the colors usually em- 
ployed for tempering certain common tools. It must be 
borne in mind, however, that the colors will not show 
unless the steel is clean and the object to be tempered 
should always be brightened by emery or similar meth- 
ods. It is also hard to judge the colors by artificial 
light, and tempering should, therefore, be done by day- 
light. 

Melted lead and tin in varying proportions makes an 

349 



Tempering baths. 

excellent heating bath for tempering, for as lead melts 
at 612 R, various degrees of the melting mass may be 
determined by adding more or less tin. If a layer of 
powdered charcoal is spread over the surface oxidation 
of the lead will not occur and there will be little waste. 
Boiling linseed oil may be used for a temperature of 
about 600 F., while sulphur, tin, zinc, antimony, etc., may 
be employed for obtaining definite heats. Where a large 
object is tempered the heat cannot be judged by color, 
and in such cases the object may be placed upon a small 
piece of bright steel — an old saw blade is good — and 
the color assumed by this will act as an index. Air-tem- 
pering furnaces, electric ovens, oil heaters and various 
other methods of accurate heating are now on the mar- 
ket, as well as a sand-tempering machine, in which a 
rotating drum is heated by gas while sand or ground 
stone is sifted in streams upon the objects being treated. 
The drum rotates slowly over the flame and pockets, 
provided with perforations, pick up the sand as it ro- 
tates and sift it as they reach the top. The work under 
treatment is placed in a wire basket in the drum, when 
small pieces are heated, but large objects rest upon the 
bed of hot sand and move constantly about by the rota- 
tion of the drum. 



350 



Colors for tempering. 

Table for colors for tempering tools. 



Approximate color. 



Yellow. 



Straw yellow 



Brown yellow. 



Light purple. 



Dark purple. 



Pale blue. 



Blue. 



Kind of Tool. 



Brass scrapers, lancets, steel 
gravers, burnishers, small turn- 
ing tools, steel planers, hammers, 
ivory-cutting tools. 

Slotters for metal, paper cut- 
ters, shear blades, engraving 
tools, boring tools, bone cutters, 
screw dies and taps. 

Leather cutters, chasers, in- 
sert saw teeth, reamers. 



Rock drills, bits, pocket 
knives, stone tools, twist drills, 
hard-wood moulders and plan- 
ers, dies and punches, gouges, 
plane irons. 



Circular saws for metal, brass 
drills, augers, drifts, circular 
wood cutters, dental and surgi- 
cal instruments, cold chisels, 
axes, gimlets. 



Bone saws, chisels, needles, 
soft wood cutters. 



Hack saws, screw drivers, 
wood saws, springs. 



351 



Electric and Salt Bath 
Furnace and Ovens. 




Electrical Heating for Hardening and Temper- 
ing ; Salt Bath Furnaces ; High Speed 
Tools; Grinding Tools ; Emery Wheels and 
Speeds for Same; Carborundum Wheels; 
Case Hardening; Objectionable Features 
of the Common Process; Browning and 
Bluing Steel. 

The rapid advancement in modern steels and their 
treatments has developed innumerable accessories and 
appliances for handling the materials and for rapid and 
accurate treatment. Prominent among these appliances 
are the electrical and salt-bath furnaces and ovens. The 
salt-bath furnaces consist of a device heated by elec- 
tricity, gas, oil or other methods, in which is a crucible 
containing fusible salts, such as barium chloride, sodium 
chloride, potassium chloride, etc., in which the steel may 
be heated. As various salts and combinations of salts 
fuse at different temperatures, it is evident that almost 
any certain degree of heat may be obtained by this 
method. Most of the salt-bath furnaces are controlled 

352 



Salt baths. 



by pyrometers, while others are regulated by an elcctri- 
cal switch ampmeter. A form of this type of electrical 
salt bath is shown in Fig. 166. This has an adjustable 
controller that will produce bath temperatures between 
482 and 2462 de- 
grees F. and consists 
of a crucible sur- 
rounded by asbestos, 
which is covered with 
fire clay and sur- 
rounded by an iron 
jacket. Two low 
carbon electrodes, 
while immersed, fur- 
nish the heat. As a 
direct current pro- 
duces electrolysis in 
these baths a single- 
phase alternating cur- 
rent is used, which, 
at starting, may re- 
quire 70 volts, but for 
maintaining the tem- 
perature requires but 
25 volts. In starting 
this furnace, after the 
bath is filled with 
salts, a small piece of 
carbon is pressed 




Fig. 166. Salt bath furnace. 



against one of the electrodes by means of an auxiliary 
piece of carbon held in the hand, as shown at B; this pro- 
duces an incandescence in the carbon and melts a channel 
across the salts. While melted salts have a high electri- 

353 



Electric furnaces. 

cal conductivity, the dry ones are poor conductors, thus 
requiring this method of starting. 

Electrical furnaces are made in various patterns and 
of all sizes and furnish a most cleanly, accurate and con- 
venient method of heat treating. 

Various methods of producing heat are employed, 
varying from the salt bath already employed to special 
furnaces for heating hollow and intricately shaped ob- 
jects. In heating hollow objects by ordinary methods 
there is great difficulty in evenly heating and in prevent- 
ing cracking from too sudden application of heat. By 
electrical methods these troubles are overcome, for the 
hollow tool may be placed over a rod and the current 
gradually increased until the proper temperature is 
reached, when the current may then be shut off slowly 
until thoroughly cooled. In operating any furnace a 
pyrometer of some sort is essential if an even and exact 
temperature is to be obtained. Modern pyrometers are 
of various forms and types, including electric-thermo, 
radium, electrical-resistance, color-screen and chemical. 
The electrical types are well known and widely used, 
but the color-screen and chemical forms are not so fa- 
miliar. The former consists of numerous cells contain- 
ing dyes, which absorb all the light of the color given 
off by a certain temperature of a heated object, and 
which is thus rendered invisible when viewed through the 
cells. On raising the temperature a portion of the light, 
due to an alteration in color, passes through the cell, thus 
rendering the object visible. Usually two pairs of cells 
are used, one pair being adjusted to a higher tempera- 
ture than the other and the desired temperature being 
half way between the two. As the cells are marked with 
the temperature they represent the furnace and steel will 

354 



Pyrometers. 

be at the proper heat when the observation opening is 
visible through one pair of cells and invisible through the 
others. When using one of these pyrometers with a 
single pair of cells the proper temperature may be as- 
certained when the work appears visible as deep crim- 
son. Chemical pyrometers are of various forms, one of 
the cheapest and handiest being merely a cylinder of 
some salt, which is placed in a receptacle in the furnace 
and the furnace is then heated until the salt fuses. As 
long as the salt remains liquid the proper, or at least a 
sufficiently high, temperature is certain, for the cylinders 
are composed of various salts of known fusible tem- 
peratures and plainly marked. 

By using three of these cylinders of different melt- 
ing points an absolutely even heat may be obtained in- 
definitely, for as long as the lowest-limit cylinder and 
correct cylinder remain liquid and the excess-temperature 
cylinder remains solid the heat is known to be up to and 
not beyond that desired. 

Great care and experience is required in grinding tools, 
and with the advent of modern high-speed machine tools 
and the various alloy steels and Tungsten tool steel, the 
grinding has become an art in itself. Nowadays emery 
wheels have given place largely to carborundum, and 
as these wheels can be obtained in practically any size or 
shape there is no excuse for not grinding your tools cor- 
rectly. Emery and carborundum wheels should, how- 
ever, be operated at definite speeds, and while it is best 
to ascertain the proper speed, grain and size of each 
wheel from the manufacturer the table or chart, Fig. 167, 
will give an idea of the ordinary speed required for 
emery wheels. 



355 



Emery wheels. 



Fig. 1 68 shows some useful forms of wheels for 
various tools, and by following the directions furnished 



3200 


































3000 












































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2800 


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2600 


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2200 




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V 5 


£ 


V 






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V* 3 




















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X 


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T 






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$ 












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1000 








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800 






























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600 






























































400 

































10 12 14 16 18 20 22 24 26 

DIAMETER OF WHEELS 

Fig. 167. Emery wheel speeds. 



356 



Emery wheels. 




by specialists in this work most satisfactory results will 
be obtained. 

High speed tool steel is designed and manufactured 
especially for rapid cutting in machines and is a self- 
hardening product, usually of tungsten steel alloy. Each 
manufacturer has his 
own formulae and pro- 
cesses, and there is more 
or less variation in the 
treatment for each in 
hardening and temper- 
ing, as well as in the 
rapidity with which 
these tools may be op- 
erated and the amount 
of work they are cap- 
able of performing. It 
is impracticable to fur- 
nish complete data or 
directions in the present 
volume, but the follow- 
ing table and directions 
regarding the well- 
known "Novo" brand 
may be of interest and 
value, and is a fairly 
good example of this 
class of tools" as a 
whole. 

Table of tests of 
"Novo" steel on 8-in. 
high-speed power lathe. 
Job consisted in turning 



r~— t^~ : ; 



J 



<~_ — ..,,,, I ! ZT~ _ 7~> 




Fig, 168. Emery wheel shapes. 



357 



Novo steel. 

a forged steel dynamo spindle head of 0.40 carbon steel, 
7% in. diam. x 6 in. wide, the whole work being done 
with ij^-in. square tool, which was merely reground 
twice. 



Speed, feet 

per 

minute. 


Transverse Revs. 

per inch of 

feed. 


Depth of cut. 


475 


220 


1/16-in., 


twice across 


650 


220 


l/32-in., 


twice across 


800 


220 


1/64-in., 


twice across 


500 


220 


1/16-in., 


twice across 


500 


220 


1/16-in., 


twice across 


500 


132 


1/16-in., 


twice across 


450 


220 


3/3 2 - in -> 


twice across 


800 


220 


1/64-in., 


three times across 


100 


220 


9/32-in., 


twice across 


100 


132 


9/32-in., 


twice across 


100 


80 


9/32-in., 


twice across 



A Novo punch will punch from 800 to 2,000 holes 
through nickel-plated armor plates i-inch thick; a Y\- 
inch punch will punch 56,000 holes through ^4-inch 
structural steel ; a 3^-inch drill at 650 revolutions will 
penetrate 4 inches of cast iron in 14 seconds. Three- 
inch cast iron can be regularly pierced by ^2 -inch drills 
at the rate of 18 inches per minute, and often at rate of 
25 inches. 

For hardening a heat of about 2300 F. is employed 
and cooling is in cold air blast, but good results are 
obtained by quenching in fish or lard oil. A most im- 
portant point is to avoid all contact with water through- 
out hardening and heating operations. Grinding should 
be done on a wet wheel. This steel is furnished in all 

353 



High speed tool steel. 

sizes of flat, round, square, triangular, octagonal, dia- 
mond, bevel and irregular sections. ''I" and "Z" sec- 
tions, from which tools are made without forging by 
merely grinding and hardening, are particularly desir- 
able, as there is no waste or breakage, and tools from 
such shapes are as strong and rigid as if solid and are 
much lighter. The "I" sections saving 30% in weight 
and the "Z" 40%. 

The unannealed steel is glass-hard, but is readily ma- 
chined when annealed. The process known commonly as 
"case-hardening" is for the purpose of infusing soft 
steel or iron with a small amount of carbon for increas- 
ing the hardness of the surface. Many parts of auto- 
mobiles, guns and other objects are thus treated, for by 
using a soft, low-carbon steel in the machine work a 
great deal is saved in expense, and by afterward case- 
hardening a very hard, long-lived bearing or wearing 
surface is produced. The usual and old method of case- 
hardening was to use calcined bone, leather or similar 
material and heat the object, embedded in this material, 
to a red heat. The animal matter then gave off the car- 
bon, which was absorbed by the steel or iron. Unfor- 
tunately, animal charcoal, while rich in carbon, also con- 
tains considerable phosphorus, which has a strong af- 
finity for iron or steel, and is most objectionable in it. 

While "red-shortness," or brittleness under heat, is 
due to too much sulphur in the iron, "cold-shortness," 
or brittleness when cold, is due to phosphorus ; and 
while the former may be eliminated by using fuel free 
from sulphur, by using coke, charcoal or gas, phos- 
phorus is very hard to remove, and in the open-hearth 
process is prevented from combining with the steel by 
using a lining to the furnace which has a stronger at- 

359 



Finishing. 

traction for phosphorus than has the iron itself. In 
all modern processes the greatest care is taken to elimi- 
nate this undesirable element from the metal and, having 
taken this trouble, it appears foolish to deliberately use 
a material for hardening which will bring about the dele- 
terious results that the steel manufacturers have spent 
time and money to prevent. Modern chemical products 
for case-hardening can now be procured which contain 
only carbon and alloy elements, and wherever the high- 
est grade work in case-hardening is required such ma- 
terials should be employed. 

Where mere color, with the thinnest possible sur- 
face-hardening, is desired for a finish to steel, bone- 
charcoal, or better still, cyanide of potassium, may be 
employed, but for high-grade, lasting work the best 
process is the cheapest in the end. 

In this connection it may be well to mention the 
fact that many steel workers send out beautifully made 
and finished products which are merely ground and pol- 
ished and soon become rusty or corroded, even with the 
best of care. Gunmakers and others have long ago 
adopted various methods of coloring their products by 
processes known as "browning" and "bluing." When 
properly done these colors are quite permanent and wear 
a long time and resist corrosion far better than polished 
or bright steel objects. For the benefit of those unfa- 
miliar with coloring methods, as well as for amateurs de- 
siring to "brown" or "blue" steel objects that are un- 
colored, the following recipes and directions are given : 

Hard steel tools may be given a beautiful glossy 
black by the use of wax or oil, but as this treatment soft- 
ens the tools somewhat they should be made a little too 
hard before treatment. The best and most durable color 

360 



Bluing and browning. 

is obtained by first polishing the object after hardening 
and when it assumes the proper tempering color it should 
be dipped in melted yellow wax. The wax should then 
be burned off by quick exposure to flame and this process 
repeated until the rich black color is obtained. The only 
difficulty encountered is in burning off the wax quickly 
enough to prevent overheating after tempering and with 
practice this can be readily accomplished. When the 
color is satisfactory the tool should be cooled in water, 
rubbed with an oily rag and dried. 

Another process for imparting a deep blue or black 
is as follows. Have the object perfectly clean and free 
from rust, oil or grease and dip pr swab over it the fol- 
lowing mixture : 

Bismuth chloride i part 

Mercury bichloride 2 parts 

Copper chloride I part 

Muriatic acid 6 parts 

Alcohol 5 parts 

Water to make 64 parts. 
The color obtained by this formula is very lasting 
and proof against oxidization. 

Small articles may be blued by placing them on a 
red-hot iron plate or bar laid across a tub or other re- 
ceptacle filled with water. As soon as the articles to be 
colored assume the proper tint they should be dumped 
quickly into the water. 

The objects to be treated should always be previously 
cleaned and polished and should be placed on the hot plate 
with polished side up. 

Small screws, etc., may be blued by placing them 
head up in a ladle or other receptacle partly filled with 

361 



Bluing formulae. 

brass filings and exposing to heat until the proper color 
is obtained. A simple way to accomplish this is to drill 
holes in a ladle just large enough to receive the screws 
and then after placing them in the holes fill around them 
with the filings. 

Bluing may also be accomplished by the following 
method : 

Crystallized chloride of iron 2 parts 

Solid chloride of antimony 2 parts 

Gallid acid 1 part 

Water 4 to 5 parts 

Apply with sponge and dry in the air. Repeat the 
process until the proper tint is obtained: wash with 
water: dry and polish with linseed oil. 

Browns may be obtained in various ways but the 
following will be found to answer all ordinary require- 
ments : 

U. S. ORDNANCE FORMULA. 

Spirits of wine i 1 /^ ounces 

Tincture of iron iy 2 ounces 

Corrosive sublimate 1V2 ounces 

Sweet spirits nitre i l / 2 ounces 

Sulphate of copper 1 ounce 

Nitric acid Y\ ounce 

Mix in 1 quart warm water and keep in glass jar. 
To use, the steel should be thoroughly cleaned with 
caustic soda to remove any traces of grease and then 
carefully polish with emery paper. Apply the mixture 
with sponge or rag and expose to air for 24 hours. Rub 
off the outer rust and rub with a scratch brush. Repeat 
the operation twice or more if necessary and finally wash 

362 



Browning steel. 

in boiling water, dry rapidly and rub with linseed oil or 
apply transparent lacquer. 

Sulphate of copper, sweet spirits of nitre, and dis- 
tilled water in the proportion of one ounce of the first two 
to one pint of water, repeatedly applied and dried for 
intervals of a few hours and finally rubbed with oil, will 
also impart a rich brown color. 

If the color after tempering an article is uneven or 
in other ways not satisfactory, it may be altered by 
blanching or whitening by dipping in a bath of hydro- 
chloric acid and afterward heating to the proper shade. 

Special Steel Treatments for Ball Bearings and 
Similar Purposes; Special Steels for Auto- 
mobile and Gas Engine Construction ; 
Various Useful Hints for Working Steel. 

The automobile and gas engine require specially high 
grade, hard, tough steels in their construction and in ball 
bearings, especially, the greatest care should be taken to 
select the most perfect and suitable steel and to harden 
and temper the cones, races and balls with the utmost 
uniformity and care. 

If the balls are too hard they will crack or chip, caus- 
ing the bearing to rapidly break down, while if too soft 
they will wear out of true and ruin the bearing. Cones or 
races that are too hard, or too soft, will act in the same 
way, while unevenly hardened races or cones will wear 
rough in spots, a ball will then soon break or chip and 
the bearing be ruined. Some makers merely case-harden 
the surface of the cones after turning from tool steel, and 

363 



Steel for bearings. 

while for light loads such work often answers fairly 
well, the thin layer of hard steel on the surface soon 
breaks through under heavy loads and ruins balls and 
bearings. 

The best makes of bearings, such as those produced 
by the Bantam Anti-friction Co. and others, are made 
from special chrome steel of great strength and tough- 
ness and are carbonized or "case-hardened" with the 
latest and most improved methods, and in furnaces 
equipped with accurate pyrometers, and are quenched 
with oil or water baths. Carbonizing in these factories is 
carried to any desired depth by use of the scleroscope 
while heating is carried on for five, six, eight, ten or 
twelve hours according to the size and depth of the work. 
Bearings made in these careful, accurate, up-to-date shops 
are remarkable for their strength, wearing properties and 
silence in operation and if properly adjusted and lubri- 
cated are almost free from friction and last almost 
forever. 

In automobile construction high grade chrome, 
nickel and vanadium steels are used and practically each 
maker of steel and each manufacturer of automobiles 
employs distinct treatments. Gasoline engines for high 
grade automobile and marine use call for the finest and 
strongest steel while the motors used in aeroplanes de- 
mand an even higher grade of material. These motors 
operate at speeds of from iooo to 1800 revolutions per 
minute and under terrific strains and great heats, and 
when it is realized that some of the multiple cylinder and 
rotating engines deliver as many as ten thousand explo- 
sive impulses per minute and produce one horse-power 
for every two pounds of weight, we can appreciate the 
great strength and durability required of the materials 

364 



Steel for gas engines. 

used in their construction. To produce cylinders and 
parts of sufficient strength and lightness, they are usually 
turned and bored from solid steel bars while such parts 
as crank shafts, cam rods, etc., are cut from solid ingots 
of chrome nickel steel. Krupp steel from Germany and 
nickel chrome steel from England are widely used and 
such steel must be capable of showing a strength of from 
150,000 to 170,000 pounds per inch to be satisfactory. 

Even these high grade steels must be treated with 
the utmost care in heating, hardening and tempering, for 
the slightest unevenness or inequality will result in dis- 
aster and death in most cases. In fact the treatment and 
working of modern alloy steels for gas engine use is a 
special art in itself, and while Americans lead in steel pro- 
duction our mechanics have never yet attained the high 
efficiency of alloy steel treatment that is found in the 
best European mechanics. 

Every artisan or mechanic will from time to time 
hit upon new and valuable methods or "wrinkles" for ac- 
complishing various results that are of great value to his 
fellows when they are made public. Many of these are 
never known outside the shop wherein they were devel- 
oped and when now and then one is published it usually 
escapes the notice of innumerable workers to whom it 
would be of great use. The following are a few of the 
many hints that may prove valuable to steel workers, 
especially in small shops, and each has been furnished by 
competent men who have tried them repeatedly with 
success. 

To case-harden parts of an object only : First coat 
the parts to be hardened with japan or lacquer, and dry. 
Next electroplate the object with copper or nickel, thus 

365 



Shop hintSo 

covering the parts that are to remain soft with the metal. 
If the object is then case-hardened the nickel or copper 
prevents the carbon from reaching the steel and thus the 
parts so protected remain soft. 

Steel wire may be hardened by. passing through a 
lead bath, at a temperature of 1200 to 1500 degrees F., 
which has been covered with a layer of chalk or charcoal. 
If desired hard, it is dipped in water ; if elastic, in oil. 

To harden without scale: Tool-steel articles which 
are polished may be hardened without scaling by dipping 
in water and then in a mixture of equal parts of fine corn 
meal and common salt. Heat the coated object in a fire 
until the mixture melts and then dip again in the mixture 
after which it can be heated to the hardening point with- 
out scaling. When the object is cooled in water or oil 
the mixture comes off, readily leaving the object as 
smooth and polished as before treating. 

By using a mixture of glycerine, 80 parts ; salt, 5 
parts ; sal ammoniac, 1 part ; concentrated muriatic acid, 
y 2 part; and water, 10 parts (by weight), as a bath for 
quenching, no reheating of the steel is necessary. 

Burnt cast steel may be restored by bringing to a red 
heat and sprinkling with a mixture of red chromate of 
potassium, 32 parts; saltpeter, 16 parts; aloes, y 2 part; 
gum arabic, y> part, and rosin, 1 part. 

Very minute cracks, flaws and holes in tools or steel 
may be rendered easily visible by dipping the object in 
kerosene; then wipe dry and rub with powdered chalk. 

366 



Shop hints. 

The kerosene that has penetrated the invisible cracks will 
ooze out and trace its position on the chalk in a dark line. 

For drilling exceedingly hard metal a cast steel drill 
should be used, heated to a cherry red, scales rubbed off 
and the point dipped in mercury and then quenched in 
cold water. 

Steel may be frosted or etched by a mixture com- 
posed of vinegar, 150 parts; blue vitriol, 30 parts; alum, 
8 parts ; salt, 12 parts ; to which a few drops of nitric acid 
are added. By allowing the liquid to remain a longer 
or shorter time, shallow or deep lines may be cut while 
a very short treatment gives a beautiful frosted surface. 

Steel and iron may be readily distinguished by filing 
with a clean new file over a flame. Steel filings will 
crackle as they burn, whereas iron filings burn brightly 
but will not crackle. 



367 



Index to Contents. 

(See Index also to new matter added to Fourth Revised Edition — including 
High Speed Steels. ) 

Action of charcoal on steel 36 

Cyanide ... . . . . '. 10 

Aging of gauges 196 

Steel 241 

Agitated baths 90-91-93 

Air annealing 7i 

Air blast for cooling 280 

Should not strike steel 35-63 

Air blasts cause cracks 299-302 

Air hardening steel 278 

Annealing 28 1 

Air jet in case hardening 233 

Alloy steels 277 

Anneal at uniform heat 84 

Annealing 27 1 

After blocking out ' 301 

Between boards 73 

Methods of 71 

Roughing out 78 

Annealing in ashes 72 

Cold water 73 

Crucibles 97 

Furnace — danger of 74-75 

Gas furnace 74-75 

Iron boxes 75-76-77 

Lime 72 

Machinery steel 81 

Object of 71 

Self-hardening steel 28 1 

Sheet steel 270 

Wrong way. 81 

Arbors and mandrels , .219-220 



Arbors for saws 286 

Arbors — taper 187 

Appliances for case hardening 242 

Ashes for annealing 72 

Attempting the impossible 127 

Augers 287 

Axes 287 

Axles — case hardening of 246 

Balls — case hardening of 242 

Barrel for hardening bath 256-257 

Barrels for guns 287 

Baskets for hardening Ill 

Bath for case hardening small pieces 229 

Cooling mandrels, etc 191 

Grooved rolls 194 

Hardening taps 157-158-160 

Springs 86 

Toughening 87 

Bath of oil for springs 263-264 

Baths for case hardening 254 

Baths for hardening. 

Brine 86-89 

Citric acid 87 

Hardening 85-86-87-96 

Hardening dies 133-135-136 

Heated 66-92 

Heat for best work 156 

Lead 96 

Mercury 85 

Oil 86 

Oil and water 88 

Poisonous baths 87 

Saltpeter 87 

Springs 260-26 1 

Sulphuric acid bath 87 

Water 86 

With liquid in motion 90-91-93 

Bench vises — jaws for 29 1 

Bessemer steel — case hardening of . 238 

Hardening Ill 

Not good for tools 275 



Best steel for mandrels or arbors 189 

Punches 142 

Bevel gears for bicycles 235 

Bicycle axles , 246 

Chains 239 

Cones— hardening 202 

Crank testing 82 

Parts — case hardening 234 

Blacksmiths' chisels • 287-288 

Forge for hardening dies 129-130 

Forge — heating in 35 

Hammer 290 

Hardies 291 

Punches .'. 294 

Blades of knives 290 

Blame — shifting of 80 

Blaming the hardener 303 

Blanking dies 214 

Blanking press dies 289 

Blanking work punches 294 

Blister steel 276 

Blocking out work for annealing 78 

Blow pipe and candle for tempering 162 

Blow pipe and spirit lamp 44^-5 

Boiling water for springs 265 

Bolt dies 289 

Bone 223 

Black for case hardening 223 

Cast iron in . . 316 

Charred 314-315 

Expended 316 

Packing steel in 316 

Preserving 316 

Should never be used in pack hardening 250 

Borax — substitute for 313 

Boxes for heating dies 132 

Pack hardening 206-209 

Box for case hardening 227-239 

Hardening springs 263 

Heating swaging dies 224 

Brine bath 86 

Brittleness ■ 56 



Brittleness — due to phosphorus 83 

In wood-working tools 200 

Bunsen burner 44-45 

Burns from cyanide — caution 110 

Burnt steel — restoring 298 

Bursting from internal strains 65 

Cams of low grade steel 24 1 

Candle and blow pipe for tempering 162 

Carbonaceous paste 46 

Carbon and quality 22 

Best for various tools 284 

Necessary for good results 29 

Penetrates iron 275 

Percentage of 15-20-21-29-33 

Surface 63 

Careful hammering 69 

Carelessness 303 

Careless workmen 17 

Carriage springs t 296 

Case hardening 225 

Baths 254 

Bicycle parts 235 

Furnaces t 253-254 

Gas pipe 226 

Imitation of Ill 

Machine nuts 251 

Many small pieces 229 

Portion of piece 248 

To leave soft places 249-250 

Cast iron bad for steel 206 

In annealing 76-81 

Cast steel 286 

Catch pan in baths 229-256 

Causes of trouble 297 

Cautions about lead bath 100 

Cemented steel 275 

Centering steel 23-24 

Centers for lathes 287 

Of mandrels or arbors should be hard 191 

Chain blocks 239 

Chain studs 247 



Charcoal 232 

Action of on steel 36 

Annealing 75-76-77 

Prevents dross 101 

Charred bone for colors 314 

Leather for annealing 85 

Leather for heating dies 132 

Leather — making 313 

Leather toughens steel 239 

Charring the bone .315 

Cheapening cost of production 8 

Cheap steel 31 

Chilled iron— steel for 28 1-282 

Tools for 293 

Chisels for cutting steel 287 

Chisels for wood 287 

Chisel temper 27 

Choosing steel 28 

Chuck jaws 29 1 

Cigars — effect on steel 87 

Circulation of water necessary 256-257 

Citric acid bath 87 

Clay for filling corners 176 

Clean fires 302 

Clock springs — hardening • 260 

Coals not always good 63 

Coke for high carbon steel 37 

Cold air blast cracks steel 35-63 

Baths not usually advisable 1 14-300 

Bending of springs 269 

Causes cracks 299 

Chisels 287-288 

Water annealing 73 

Water bad for springs 259 

Work 287-288 

Collars to prevent case hardening 251 

Color blindness , 11 

Coloring gun frames 109 

Colors denote temper 1 17-123 

For springs 269 

In case hardening 233 

Obtained with cyanide 108 



Colors on case hardened work 258 

On malleable iron Ill 

Reason for 124-125 

Visible 117 

Cooling case hardened work 234 

Deep hole in die 94 

Device for gauges 196 

Dies for screw cutting 151 

Flat plates 179 

Grooved rolls 193 

Gun springs ... 1 82 

Half round reamers 163 

In air blast 280 

In bath 14 

In small bath 94 

Jaws of hardening device 181 

Milling cutters 166 

Pieces with holes near edge 199 

Plate mounted on springs 181 

Shank mill ' 94 

Springs 262-263-264 

The oil bath 263-264 

Thin pieces 245 

With dirty water 95 

Commercial bars vs. hammering 70 

Common error .' 279 

Compounds for hardening 88 

Cones for bicycles— hardening 202 

Considerations in hardening 127 

Continued heating 84 

Continuous or agitated baths 90-9 1-93 

Contraction and expansion 12-14 

Converted steel 275 

Correcting wrong annealing 82 

Cost of production 8 

Testing steel 33 

Counterbores 158-187-188 

Countersinking too deeply 187 

Covering paste 46 

Cracking in lead bath. 100 

Liability of 27 1 

Of hollow articles 175 



Cracking of round pieces 62 

Cracks 14-35-298-299 

Cause of 305 

Prevention of 203-204 

Where they occur 100 

Crank axles — hardening 235-246 

Critical temperature 13 

Crucible cast steel 276 

Steel 286 

Crucibles — annealing 97 

Should always be emptied 101 

Used for lead baths 97 

Crushing grain in hammering 69-70 

Cutters for milling machine 288 

Glass 288 

Pipe cutting 288 

Cutting pliers 29 1 

Point of tools 7 

Tools — hardening 86-87 

Tools of machine steel 241-243-272-274 

Cyanide — action of 106 

Bath best for cutting tools 105 

Bath for watch springs .267 

Coloring with 108 

Hardening furnace 106 

Hardens surface 107 

Heated in open forge 50 

Heating bath — advantage of 46-108 

Of potassium a poison 107 

Of potassium bath 105 

Of potassium for case hardening 227 

Of potassium furnace. 51-52 

Should be chemically pure 106 

Solution prevents lead sticking 98-103 

Dampers 39-40 

Danger from small fire 190 

Cracking removed 138-139 

In steel welds 311 

Of cast iron in annealing 76-81 

Overheating in annealing 74-75-83 

Decarbonized surface 23-28-35-45-61-64 



Deep case hardening 232 

Deep fire best 35 

Defects in steel— lack cf 302 

Degrees of hardness 284 

Depth of hardening 89 

Detecting time of cracking 100 

Device for cooling thin plates 179-180 

Die or punch hardest ? 140 

Dies — baths for hardening 133-136 

Blanking press 289 

Boxes for heating 132-224 

Cracking from internal strains 154 

Drawing 290 

Drawing temper of 139 

Drop forging 290 

For cartridges and other work 197 

Forming 144 

For punching 24 1 

Furnace for 130-131-137 

Heating in charred leather 132 

Hardening 149-204-2 15-22 1 

Heating 40 

Heating box for 145 

Hobs for 29 1 

Method of cooling 151 

Methods of hardening 129 

"Spring" 153 

Starting scale before hardening 134 

Tempering 153 

Tongs or grappling hooks 135-136 

To prevent cracking 138-139 

Punch press work 138-143-249 

Ring 144 

Ring — furnace for 145 

Screw cutting 289 

Swaging 289 

Threading bolts 289 

Difference in steel 16 

Different results in case hardening 237 

Steels 26 

Difficult pieces to harden 217-218 

Dipping thin pieces 245 



Dirty water for cooling 95 

Disc cracked in grinding 306 

Dont's 280-301 

Doubts about steel 274 

Drawing dies 290 

Forming dies 144 

Milling cutters 167-168 

Punches 142-143 

Ring dies 147-148 

Slitting saws 183 

Springs 265-266 

Temper 56-1 16 

Temper of dies : 139 

Temper of T slot cutters 174 

Draw knives 228 

Drill rod not good for punches 142 

Drills for rock 290 

Twist 290-309 

Drop forging dies 290 

Dull cutters spring work 303 

Eccentric centering 24 

Holes in articles 198 

Economy in heating 45 

Of inspection, 33 

Effect of continued heating : 84 

Heat on hammered steel 69 

Oil on temper color 125 

Slight changes in heat 123-124 

Emergency annealing 74 

Emery wheel— use proper .' 307 

Equalizing heat of lead bath 106 

Error — common 279 

Even heating by lead bath 92 

Exact tempering by thermometer 123 

Examples of hardening 127 

Expansion and contraction ; , 12 

Expended bone for Bessemer steel 238 

In annealing 83 

Experience 16 

Experiment in partial hardening 248 

Extravagant economy 24 

Extreme hardness 285 



Falling heat 62 

Files 29G 

Method of hardening 99 

Fillets in counterbores 187 

T slot cutters, 172-173 

Filling corners with graphite or clay 1 76 

Fire-clay to prevent hardening 249-250 

Fire cracks 299 

Fixture for handling ring dies 147 

Fixtures for use in hardening 201-202 

Flashing springs 265 

Flat plates — methods of cooling 179 

Springs 270 

Flexibility of hardened steel 66 

Fluxes 3 10-3 1 1-313 

Forging 68 

And tempering at once 71 

Dies (drop forging) 290 

Improper 300 

Self-hardening steels 279-280 

Troubles 68 

Forming dies 144 

Tools 221 

Fuels 36-37-38 

For hardening baths 96 

Fumes from cyanide furnace 52-53 

Lead baths 47-51 

Furnace for case hardening 242 

Case hardening 253-254 

Dies 130-131-137 

Heating baths 47-49-51-52 

Heating springs 262 

Heating taps 159 

Heavy dies 136-137 

Lead heating 96 

Pack hardening 210 

Ring dies 145 

Furnaces — location of 54 

Gas as fuel 37 

Blast for heating 42-43-44-45 

Furnace for dies , 137 



Gas pipe for case hardening 228 

Gauges— aging of 196 

Crack from grinding 305 

Hardening ring 195-196 

Packing for hardening 240 

Snap and ring 215-216-218 

Gear for chainless bicycles 235 

Genesis of pack hardening 203 

German steel 276 

Glass bath for hair springs 267 

Cutters 288 

Hardening bath for watch springs 54 

Heating baths 46 

Government method of hardening files 98-99 

Grain of tool steel 55-56-57-61 

Granulated raw bone 243 

Graphite for filling corners 176 

Grinding cracks tools 305-306 

Taps to show color „ 161 

Tools right 307 

Gripping jaws 292 

Grooved rolls— hardening 192 

Gun barrels 287 

Gun frames — coloring 109 

Hardening 252 

Springs — cooling 182 

Hair springs 267 

Half round reamers 162-163 

Hammer — blacksmiths' 290 

Machinists' 291 

Refining 69-70 

Hammered steel 69 

Handle-bar binders 235 

Handling heavy dies 135-136 

Maximum amount of work 104 

Ring dies 146 

Harden at lowest heat 126 

Hardened work — straightening 115 

Hardening 22 

Arbors 189 

A screw driver : 184 



Hardening baths 85-86-87-96-105 

Bessemer steel Ill 

Between plates 1 78 

Bicycle parts 235 

Compounds 88 

Cutting tools 86 

Depth of 89 

Dies 129 

Dies without ' ' twist " 150 

Eccentric pieces 198 

Files 98-99 

Fixtures 201-202 

Grooved rolls 192 

Half round reamers 163 

High carbon steel 285 

Holes '. 90-93 

Hollow mills 175 

Hot water 113 

In baskets Ill 

Large pieces 35 

Lead 96 

Locally 252 

Long tools 30-104-154-155-258 

Machine for thin articles 180 

Machinery steel 1 10-1 1 1-225 

Malleable iron 110 

Mandrels, arbors, etc 189 

Milling cutters 164-165 

Places 248 

Ring dies 144-145-147 

Saws 178 

Screw cutting dies 149 

Shank mills 169-170 

Small tools— mixture for 98 

Springs 259-260-26 1-262-263-264-265 

Steel 112 

Taps and dies 53-156-160-202 

Temperature of different steels 59 

The punch 141 

Thin pieces i78-244 

Walls of holes 195 

Watch springs 54 



Hardening wood-working tools 200-201 

Hardies for blacksmiths 29 1 

Hard metals— steel for 277 

Hardness — degrees of 284 

Due to cyanide bath 51 

Extreme 285 

Heat depends on carbon 55 

For welding 310 

High ' 297 

Necessary to draw temper 117 

Of lead bath — care about 102 

Rapid 298 

Refining 13-56 

Should be low as possible 13 

Slow 299 

Slowly for tempering 140-125 

"Soaking" 299 

Strength depends on 107 

Uneven 297 

Work — timing 23 1 

Heated baths 66-92 

Advantages of 156 

Heath 277 

Heating articles of irregular shape 67 

At right speed - 60-61 

Box for ring dies . . , 145 

Cyanide in an open forge 52 

Cyanide of potassium 46 

Dies 40 

Dies in boxes 132 

Dies — proper method 133 

For hardening with lead bath 96-100 

Gas blast 42-43-44-45 

Glass 46 

Grooved rolls 192 

In a forge 35 

Lead \ 46-49 

Tin 46 

Tubes in open fire 63 

Large work 45 

Long tools in lead bath 104 

Machine for slender punches 143 



Heating mandrels 186-189 

Screw dies in boxes 152 

Slender punches 143 

Small work in tubes 41-42 

Steel — methods of 34 

The baths 92 

To avoid strains 113 

Tool steel 55 

Uniformly 14-60-62 

Various substances ' 46 

Water for hardening tools 104-1 13 

Wood-working tools 20 1 

Work in cyanide bath 105 

Heavy and light portions 62 

Blows when hot 69 

Cuts 65 

Punches , 142 

Springs 265 

High carbon steel 30-278-283 

Duty steels 277 

For punches 142 

Heats 297 

Heats open grain 69-70 

Speed steel 277 

Hobs for dies 29 

Holes— hardening 90-93 

Hardening out of round 195 

In dies — cooling of 93 

In shank mills 171 

Near edge 198 

Stopped with clay 138 

Hollow articles — to prevent cracking 175 

Danger of steam forming in . 175 

Mills 174-175 

Home-made furnace for dies 131 

Furnaces 39-40-47-49-53 

Gas blast oven 44 

Lead heating apparatus 49-50 

Hot lead for hardening . 96 

Water bath for springs 265 

Work— chisels for 287 

How to case harden small quantities 226 



How to pack harden 207 

Huntsman, Benjamin 276 

Hydrocarbonated bone 233 

Identifying steel 33 

Imitation case hardening Ill 

Importance of cutting point 7 

Improper forging 300 

Heating and hammering 70 

Impure lead injures steel 97 

Increase in production 10 

Indifference of some hardeners 64 

Inspection of steel — economy of 33 

I nternal strains 65-79 

Strains in dies 154 

Iron boxes for annealing 75-76-77 

Irregular shaped work 62-67 

Jaws for bench vises 29 1 

Chucks 29 1 

Cutting pliers 29 1 

Gripping 292 

Pipe machines 292 

Screw threading dies 292 

Wire pullers 292 

Jarolinech 13-59 

Kettle for tempering in oil 122 

Key ways 307 

Knife blades 292 

Knives — draw knives 292 

Knowing it all 16 

Labeling steel 33 

Lack of ability 129 

Large baths 95 

Fire best for hardening 190 

Tanks best 139 

Work— caution about 222 

Lathe centers 287 

Tools , 292-309 

Tools — tempering 120 

Lead and crucibles 97 

Bath for hardening 96 



Lead bath sometimes unsatisfactory — why 97-102 

Furnace — handling work in 104 

Hardening furnace 47-48 

Heating baths 46-49 

Heating furnace 96 

Should be pure 97 

Sticking to work 98-102 

Too hot — caution about 102 

Leather — charring 313 

Charred for annealing 85 

For heating dies 132 

Length of time to heat 231 

Liability of cracking 27 1 

Lighter blows when cooling 69 

Lime for annealing 72 

Local case hardening 249-250 

Hardening 252 

Location of furnaces 54 

Locomotive springs 296 

Long taps — best methods for 158 

Tools — hardening 154-155 

Loss due to poor hardening 9-10 

Low carbon steel for tools 272-274 

Heats best 13 

Heats for tempering 124 

Lowest heat best for hardening 126 

Lubricating tools 309 

Machine for hardening thin articles 180 

Steel for tools 241-271-274 

Taps 296 

Machinery crucible steel 293 

Case hardening 225 

Hardening Ill 

Steel 19 

Machinists' hammer 29 1 

Makeshift oven 128 

Making a screw-driver 184 

Malleable iron — hardening 1 10-1 1 1 

Mandrels 293 

And arbors 2 19-220 

Taper 186-189 



Men who harden 15 

Mercury bath 85 

Metcalf on " refining heat " 56 

Method of cooling gun springs 182 

Cooling for hardening 89-90-9 1 

Drawing temper 118 

Heating steel 34 

Milling cutters 55-204-212-213-288-307-309 

Arbors 286 

Drawing temper of 167 

Hardening 164-165 

Machine '. 286 

Reamers or taps 304 

Mixing of different grades 28 

Mixture for color work 233 

Hardening small tools 98 

Hardening springs 260-261 

Heating wood-working tools 201 

Machine steel tools • 240-243 

Mould for casting lead 101 

Mowers 293 

Muffle furnace for heating taps 159 

Furnaces ■ 37-41 

Mushet 277 

Mysteries — absence of 25 

Nature of steel 1 1-60 

Neat's-foot oil 261 

New charcoal best 36 

Nickel-plating prevents case hardening 251 

Non-crackers 11 

Nuts — case hardening , 251 

Oil affects temper color 125 

And water bath 88-167 

Bath 86 

For case hardened work 234 

Hardening 211-212-214 

Hardening thin articles 181 

Kettle 122 

Long tools 104 

Removing strains 67-68 



Cil for hardening springs 263-264 

Tempering furnace 121 

Toughens springs 259 

Wood-working tools 200-201 

Overheated steel — restoring 298 

Overheating 13 

In annealing 74-75-83 

Oxidized steel 63 

Pack hardening 203 

Arbors and mandrels 2 19-220 

A "teaser" 218 

Bath of oil for 21 1-212 

Bicycle parts 236 

Blanking dies 214 

Boxes for 206 

Danger in cast iron 206 

Depth of hardened surface 205 

Dies and taps 2 15-22 1 

Difficult pieces 217 

Don't use bone 205 

Forming tools 221 

Furnace for 210 

Gauges 215-216-218 

Heat of boxes 210 

How to do it : 207 

Large work 222 

Long articles 209 

Mandrels and arbors 2 19-220 

Method of packing 206 

Milling cutters 212-213 

Phosphorus to be avoided 205 

Possibilities of 224 

Reamers 222-223 

Similar articles together 208 

Swaging dies 223 

Tanks should be convenient 222 

Taps and dies 215-221 

Time necessary 211 

Wiring the work 207 

Wrong way of doing 208 

Packing for case hardening 228 



Packing gauges for hardening 240 

Material 232 

Pan of sand for drawing temper 118 

Partial heating 127 

Paste for coating small tools 98 

Covering work 46 

Peculiarities of tool steel 22 

Percentage of carbon 15-20-21-29-33 

Carbons for tools 284 

Penetration of carbon in iron 275 

Phosphorus affects steel 272-283 

Bad effects of 83 

Makes steel brittle 252 

Piercing punch 141 

Pinion gear — hardening of 237 

Pipe cutters 288 

Machine jaws 292 

Pipes in steel bars 32 

Planer tools 293-294 

Plates — cooling 179 

Pliability of hardened steel 66 

Pliers for cutting 29 1 

' ' Points ' ' of carbon 21 

Poisonous fumes 47-52-53 

Potash 261 

Preventing decarbonization locally '. 46 

Dross forming on top 101 

Lead sticking to work 98-103 

Local hardening 249-250 

Springs in ring gauges 195 

Prevention of cracking 138-139 

Springing of long articles 30 

Process of annealing in boxes 77 

Production — cheapening cost of 8 

Increase in 10 

Prussiate of potash for case hardening 226 

Punch — buckling of 141 

Blacksmiths 294 

Blanking work 294 

Drawing temper of 142-143 

Hardening of 141 

Heating machine for 143 



Punch for hot trimming 294 

Sheet steel 141 

Track work 295 

Punch or die hardest ? 140 

Punch press dies 138-143-241-289 

Quality and carbon 22 

Quantity of work to be case hardened 226 

Rapid heating 60-61-298 

Raw bone contains phosphorus 252 

Razor temper 20 

Reamer — heating a long 128 

Reamers 158-162-222-223-295 

Dull cutters may spoil 303-304 

Half round 162-163 

Heating in lead bath 104 

Reasons for temper colors 124-125 

Using lead bath 100 

Reducing worn dies 197 

Refining— heat 13-56-60 

By hammering 69-70 

Temperature 13-56-60 

Reheating to draw temper 1 16 

Remove strains 65-66-67 

Reliable steel 282 

Removing lead from steel 102 

Strains from grooved rolls 194 

Rendered beef suet 26 1 

Resin 261 

Use of — caution 104-105 

Restoring burnt steel 298 

Results of case hardening 237 

Revolving furnace for drawing temper 118-119 

Ring dies 144 

Drawing temper 147-148 

Furnace for 145 

Hardening 144-145-147 

Ring gauges — hardening of 195-196 

Rings without welds 311-312 

Rising heat 62 

Rock drills - 290 



Rotting of steel 88 

Roughing out work 24-25 

Safety valve springs 269 

Sal ammoniac for case hardening 226 

Salt and cyanide bath 53-105 

Salt for case hardening 226 

Satisfactory annealing 75-76 

Saturated solution 86 

Saw arbors 286 

Saw-file temper 21 

Saws for wood 295 

Hardening of 1 79 

Steel 295 

Tempering 183 

Scale formed in dies — removing 134 

Scrapers , 295 

Screw cutting dies 289 

Hardening 149 

Method of heating 152 

Preventing twist „ . . . 150 

Screw-drivers 183-186-295 

Screws— case hardening 238 

Screw threading dies 148-229 

Seasoning of gauges 196 

" Second blue " 268 

Self-hardening steel 278 

Annealing 28 1 

Separating steel 33 

Set temper 21 

Shafts for high speed 295 

Shank mill— cooling 94 

Shank mills — hardening 169-170 

Methods of making 1 70 

With holes 171 

Shapes of steel bars 28 

Sharp corners to be avoided 178 

Shear steel 276 

Sheet steel — annealing ' 270 

Springs 270 

Shifting the blame 80 

Singing of steel in bath 90 



Slender articles — hardening 258 

Slender tools 273 

Slitting saws — drawing iemper 183 

Slotting saws — hardening of 1 76 

Slow heating 60-61-299 

Best for tempering 125 

Small bath for cooling 94-95 

Lots of case hardening 226 

Pieces — method of case hardening 229 

Taps, reamers, etc 158 

Work — heating in tubes 41-42 

Snap gauges 215-216-240 

"Soaking" 299 

Soft places on work 249-250 

Portions— leaving 248 

Soap 261 

Spots where lead sticks to steel 102 

Special preparations 232 

Steels 275 

Spermaceti oil 26 1 

Sperm oil for springs 261 

Spindles 242 

Spindle steel 295 

Temper 21 

Spirit iamp for heating 44-45 

Spoiled steel 9 

Spring dies 152 

Springing of mandrel 304 

To prevent 155 

Spring of work by dull cutters 303 

Springs— bath for 86-260-26 1 

Best steel for 259 

Carriage 296 

Clocks 260 

Colors of 269 

Danger of bending cold 269 

Flat stock 270 

Furnace for heating f .262 

Locomotive 296 

Safety valves 269 

Sheet steel 270 

Method of cooling , , . , ,,,.,,.. .262 



Springs — toughened by oil 259 

Tempering 259 

Watches 54-267 

Stamps for steel 295 

Steam forming in hollow articles 175 

Prevents cooling 93 

Steel 19 

Affected by phosphorus 272 

Air hardening 278 

Alloy 277 

Bessemer 286 

Better than ever 277 

Blister 276 

Cast 286 

Cemented 275 

Choice of 28 

Converted 275-286 

Crucible 279-286 

Difference in 16 

Different 26 

Doubts about 274 

For chilled iron 28 1-282 

For hard metals 277 

For mandrels or arbors 189 

For slender tools 273 

For various tools 282-285 

German 276 

Hammer refined 70 

(Machine)— tools 271-274 

Machinery 20 

Nature of 11 

None best for all purposes 30 

Open hearth 286 

Pliability of 66 

Saws 295 

Self-hardening 278 

Shear 276 

Spoiled 9 

Stamps 295 

Usually all right 27 

Tool 20 

To use for springs 259 



Steels — special 275 

Stiffness — how to secure 252 

Stirring lead bath to equalize heat 102-104 

Stock — keeping separate 28 

Stone work 288 

Chisels for 288 

Working tools 293 

Stop all holes in dies with clay 138 

Straightening hardened work 115 

Steel 66-301 

Work 26-30 

Work that is sprung 79 

Strains in grooved rolls 194 

Internal 65-79 

Internal — in dies 154 

Removed by reheating 65-66-67 

Strength depends on heat used 59-64 

Study of steel 1 1-18-80 

Substitute for borax 313 

Successful steel working 18 

Sudden heating is dangerous 140 

Sulphur in lead — avoid it 97 

Surface carbon 63 

Square comers in counterbores 187 

Supporting cutting edges 308 

Swaging dies 223-289 

Heating boxes for 224 

Sweeps for moving pieces of work 258 

Tallow for tempering springs 265 

Tank for hardening small work 230 

Reheating 66-67 

Tanks for case hardening 255-256 

Should be convenient 222 

Should be large 139 

Taps 296 

Brightening for color 161 

Furnace for heating 159 

Hardening 156-160-204-215-214 

Hardening bath for 157-158-160 

Machine 296 

Taper mandrels 1 86 



Temper '. 20-21-28 

Chisel 21 

Milling cutters 213 

Razor 20 

Saw file 21 

Set 21 

Spindle 21 

Tool 21 

Tempers of tools 283-284 

Temperature — critical 13 

Colors 123-125 

For drawing small dies 153 

Grades of 20-21 

Of counterbores 188 

Of lead for hardening 103 

Refining 13-56 

Tempering 116 

A screw driver 164 

At very low heats 124 

Heat necessary 117 

In a revolving furnace 1 18-1 19 

In oil 121 

Is softening 1 16-126 

Lathe tools 120 

Milling cutters 167-168 

Ring dies 147-148 

Saws 183 

Small dies 153 

Spoiled steel 82 

Springs 259-265-266 

Springs by thermometer 266 

Taps 162 

To ' ' second blue " 268 

Temporary bath for hardening 257 

Furnace for oil 121 

Tepid water for hardening 176 

Test after hardening 30 1 

Pieces 57-58-61 

Wires in annealing 76-77 

Wires when case hardening 227 

Testing a screw driver 1 85 

Bars in stock 32 



Testing bicycle crank 82 

Hardened work 82 

Heat of boxes 210-212 

Steel 33-57-58-61 

Work occasionally 244 

Thermometer — care of 266 

For gauging heat 1 19-21 1 

In spring tempering 266 

Thin articles— hardening 180-244 

Threading dies 148-289-292 

Time for heating gauges 240 

Needed for pack hardening 211 

Timing heat of work 23 1 

Tin heating baths 46 

Tool steel 20 

Heating of 55 

Temper 21 

Tools cut faster if pack hardened 204 

For chilled iron 283 

Hard work 33 

Importance of cutting point 7 

Lathes and planers 292-293-294 

Of machine steel : .241-243-271-274 

Steel for 282-285 

Stone 293 

Weakened by grinding 308 

Wood-working 293 

Tongs for hardening mandrels or arbors ..191 

Hardening thin articles 178 

Heavy dies 136 

Preventing hardening 249-250 

Toughening bath 87 

Steel 239 

Toughness — how to produce 252 

In wood-working tools 200 

Tubes for heating small work , 41-42 

Turpentine 261 

Track work punches 295 

Trimming punches 294 

Trouble — causes of 297 

Troubles from forging 68 

T slot cutters 171-172-173-174 



Twisf drills 290 

In hardening dies 150 

Types of furnaces 37-38 

Hollow mills 177 

Uneven hardening from small baths 255 

Heating 14-26-60 

Heats 297-302 

Uniform annealing heat necessary 84 

Heating 14-26-60 

Heats the secret of success 1 12 

Temperature necessary 264 

Valuable men to have 128 

Vent holes in hollow mills ■ . 176-177 

Vine-like effect in coloring 109 

Warm water for hardening 176 

Waste through improper handling 9 

Watch spring hardening 54-267 

Water annealing 73 

Bath 86 

Cooled oil bath .. 214 

May crack work 306 

Welding 310 

Heat for 310 

Rings — how to avoid .' 311-312 

Steel — don't 311 

Wine suppers and steel 87 

Wire pullers 292 

Wires for testing heat , 76-77 

Wiring pieces to be hardened , 207 

Wood saws 295 

Chisels .• . 287 

Tools 199-200-201-293 

Working augers 287 

Work done depends largely on tools » - „ . 7 

Of tool depends on heat used 126 

Workman 15 

Wrong annealing 82 

To anneal .- r • - 81 

Way of pack hardening 208 

Wrought iron —case hardening ....-- -225 



Index to 

Matter added to Fourth Revised Edition 

including High Speed Steels. 

Annealing high-speed steel 325 

Ball-bearings 363, 364 

Baths for tempering 349, 350 

Bluing and browning steel 361, 362, 363 

Carbon-influence of 320 

Carborundum wheels 356, 357 

Case hardening locally 365 

Chromium 321 

Clearance of tools 323 

Cold-shortness '. 359 

Colors for tempering 349, 351 

Cracks and flaws 366 

Critical range 340 

Cutting speed 31 8-337 

Drawing temper 336 

Drilling hard steel 367 

Electric furnaces 354 

Electrical heat for hardening 332 

Electrical ovens 352, 353 

Emery wheels 356, 357 

Etching steel 367 

Feeds 337 

Finishing 360 

Forging 328-331 

Frosting steel 367 

Gledhills tests 320 

Grinding 355, 356, 357 

Hardening 332-346 

Hardening rock drills 338 

Hardening wire 366 

Hardening without scale 366 

Hardenite 341 , 342 

Heat for forging 324-331 



High-carbon steels .340, 343 

High-speed steei 317 

High-speed tool steel 324, 357, 358, 359 

Instruction for high-speed steels 330 

Low-tungsten steel 343 

Magnet gauges 342, 343 

Magnetic properties 343 

Martensite 341 , 346 

Misleading tests 318 

Molybdenum 322 

Novo steel 357, 358, 359 

Pearlite 341 , 342 

Point of recalescence 340, 341 

Polybdenum 322 

Pyrometers 354, 355 

Quenching 340, 341 

Quenching baths 347 

Recalescence 340, 341, 344, 345 

Red-shortness ■ 359 

Restoring burnt steel 366 

Rock-drills hardening and tempering 338 

Salt baths 352, 353 

Shapes of high-speed tools 324 

Shop hints 365, 366 

Silicon '. 323 

Special treatments 365 

Speed of work 318-337 

Steel for gas engines 365 

Steels, high-speed 317 

Temperatures 348 

Temperature changes 344, 345 

Tempering 336 

Tempering carbon-steel 349 

Tempering rock-drills 338 

Tests that mislead 318 

Tools for high-speed work 323-324 

Tungsten steel 322, 340 



DIRECTORY OF SUPPLIES. 



AIR HARDENING STEEL. 

Edwin R. Kent & Co Chicago, 111. 

Ceo. R. Nash & Co New York. 

Edgar T. Ward's Sons Boston, Mass. 

BORINC TOOLS. 

Three Rivers Tool Co Three Rivers, Mich. 

CASE HARDENING FURNACES. 

American Gas Furnace Co New York. 

Chicago Flexible Shaft Co Chicago, 111. 

COUNTERBORES. 

R. M. Clough Tolland, Conn. 

DRAWN STEEL SHAPES. 

Kidd Bros. & Burger Steel Wire Co Aliquippa, Pa. 

DRILL CHUCKS. 

Edwin R. Kent & Co Chicago, 111. 

DRILLS— CORE. 

Three Rivers Tool Co Three Rivers, Mich. 

DRILLS— DEEP HOLE. 

Three Rivers Tool Co Three Rivers, Mich. 

DRILL RODS. 

Edwin R. Kent & Co Chicago, 111. 

Patriarche & Bell New York. 

Kidd Bros. & Burger Steel Wire Co Uiquippa, Pa. 

DRILLS— TWIST. 

Edwin R. Kent & Co Chicago, 111. 

EMERY WHEEL DRESSERS. 

Geo. H. Calder Lancaster, Pa. 

FORGES— GAS. 

American Gas Furnace Co New York. 

FURNACES— GAS. 

American Gas Furnace Co New York. 

Chicago Flexible Shaft Co Chicago, 111. 

FURNACES— OIL. 

Chicago Flexible Shaft Co Chicago, 111. 

FURNACES— OIL— AUTOMATIC. 

American Gas Furnace Co New York. 

GRINDERS— CUTTER. 

R. M. Clough Tolland, Conn. 



HARDENING FURNACES. 

American Gas Furnace Co New York. 

Chicago Flexible Shaft Co Chicago, 111. 

HEATING MACHINES. 

American Gas Furnace Co New York. 

HIGH SPEED STEEL. 

Wm. Jessop & Sons, Inc New York. 

LATHE AND PLANER TOOLS. 

Armstrong Bros. Tool Co Chicago, 111. 

R. M. Clough Tolland, Conn. 

Three Rivers Tool Co Three Rivers, Mich. 

MANGANESE STEEL. 

Edwin R. Kent & Co Chicago, 111. 

MILLING CUTTERS. 

R. M. Clough Tolland, Conn. 

MILLING MACHINES— VERTICAL. 

R. M. Clough Tolland, Conn. 

REAMERS. 

Three Rivers Tool Co Three Rivers, Mich. 

REAMERS— ADJUSTABLE. 

R. M. Clough Tolland, Conn. 

SHEET STEEL. 

Wm. Jessop & Sons, Inc New York. 

SPRING STEEL. 

Patriarche & Bell New York. 

Edgar T. Ward's Sons Boston, Mass. 

STEEL— TOOL. 

Edwin R. Kent & Co Chicago. 111. 

Firth-Sterling Steel Co McKeesport, Pa. 

Kidd Bros. & Burger Steel Wire Co Aliquippa, Pa. 

STEEL TUBING. 

Edgar T. Ward's Sons Boston, Mass. 

TOOL STEELS. 

Wm. Jessop & Sons, Inc New York. 

TWIST DRILLS. 

Edwin R. Kent & Co Chicago. 111. 

Edgar T. Ward's Sons Boston, Mass. 



JESSOP'S 

BEST CARBON STEEL 

and ARK speed STEEL 

For dies and high grade TOOLS 



ALWAYS PLZZ^- 1 ^mh MOST 

UNIFORM r «rs 3 £ 3^ ECONOMICAL 

ARK. 



Jessop's "Ark" High Speed Steel 

Has stood the test. Has many imitators 

BUT NO EQUAL 

Manufactured in Sheffield, England 




Tool Steel Forgings 

WM. JESSOP & SONS, Inc. 

91 John Street, NEW YORK CITY 

Warehouses throughout the United States 



>*r%» 




PRACTICAL SCIENTIFIC 
TECHNICAL 



EACH BOOK IN THIS CATALOGUE IS WRITTEN BY 

AN EXPERT AND IS WRITTEN SO YOU 

CAN UNDERSTAND IT 



THE NORMAN V. HENLEY PUBLISHING COMPANY 

Publishers of Scientific and Practical Books 
132 Nassau Street New Yor k, U. S. A. 



Any book m this Catalogue sent prepaid on receipt of 



price. 



SUBJECT INDEX 



PAGE 

Accidents 18 

Air Brakes 17, 19 

Arithmetics 20 

Automobiles 3 

Balloons 3 

Bevel Gears 14 

Boilers 22 

Brazing 3 

Cams 15 

Car Charts 4 

Change Gear 14 

Charts 3, 4, 22 

Chemistry 23 

Coal Mining 23 

Coke 4 

Compressed Air 5 

Concrete 5 

Cyclopedia 4, 20 

Dictionaries 7 

Dies 7 

Drawing 8, 24 

Drop Forging 7 

Dynamo 9, 10, 11 

Electricity 9, 10, 11, 12 

Engines and Boilers 22 

Factory Management 12 

Flying Machines 3 

Fuel 13 

Gas Manufacturing 14 

Gas Engines 13, 14 

Gears 14 

Heating, Electric 9 

Hot Water Heating 27 

Horse-Power Chart 4 

Hydraulics 15 

Ice Making 15 

India Rubber , 25 

Interchangeable Manufacturing 20 

Inventions 15 

Knots 15 

Lathe Work 16 

Lighting (Electric) 9 

Link Motion 17 

Liquid Air 16 

Locomotive Boilers 18 

Locomotive Engineering 17, 18, 19 

Machinist's Books 20, 21, 22 



PAGE 

Manual Training 22 

Marine Engines 22 

Marine Steam Turbines 29 

Mechanical Movements 20, 21 

Metal Turning 16 

Milling Machines 21 

Mining 22, 23 

Oil Engines 13 

Patents 15 

Pattern Making 23 

Perfumery 23 

Pipes 28 

Plumbing 24 

Producer Gas 13 

Punches 7 

Railroad Accidents 18 

Receipt Book 23, 25 

Refrigeration 15 

Rope Work 15 

Rubber Stamps 25 

Saws 26 

Sheet Metal Working 7 

Shop Tools 21 

Shop Construction 20 

Shop Management 20 

Sketching Paper 8 

Smoke Prevention 13 

Soldering 3 

Splices 15 

Steam Engineering 26, 27 

Steam Heating 27 

Steam Pipes 28 

Steel 28 

Superheated Steam 17 

Switchboards 9, 11 

Tapers 16 

Telephone 12 

Threads 22 

Tools 20, 22 

Turbines 29 

Ventilation 27 

Valve Gear 19 

Valve Setting 17 

Walschaert Valve Gear 19 

Watchmaking 29 

Wiring 9, 11, 12 

Wireless Telephones and Telegraphy 12 



THESE BOOKS PROMPTLY SENT PREPAID TO ANY ADDRESS IN 
THE WORLD ON RECEIPT OF PRICE. 



J^- ANY OF 



$@F*How to Remit.— "By Postal Money Order, Express Money Order, Bank Draft 

or Registered Letter. 



CATALOGUE OF GOOD, PRACTICAL BOOKS 



AUTOMOBILE 

THE MODERN GASOLINE AUTOMOBILE— ITS DESIGN, CONSTRUCTION, 
MAINTENANCE AND REPAIR. By Victor W. Page, M. E. 

The latest and most complete treatise on the Gasoline Automobile ever issued. Written 
in simple language by a recognized authority, familiar with every branch of the automobile 
industry. Free from technical terms. Everything is explained so simply that anyone of 
average intelligence may gain a comprehensive knowledge of the gasoline automobile. 
The information is up-to-date and includes, in addition to an exposition of principles of 
construction and description of all types of automobiles and their components, valuable 
money-saving hints on the care and operation of motor cars propelled by internal combus- 
tion engines. Among some of the subjects treated might be mentioned: Torpedo and other 
symmetrical body forms designed to reduce air resistance; sleeve valve, rotary valve and 
other types of silent motors; increasing tendency to favor worm-gear power-transmission; 
universal application of magneto ignition; development of automobile electric-lighting 
sys terns; block motors; underslung chassis; application of practical self-starters; long stroke 
and offset cylinder motors; latest automatic lubrication systems; silent chains for valve 
operation and change-speed gearing; the use of front wheel brakes and many other detail 
refinements. 

By a careful study of the pages of this book one can gain practical knowledge of automobile 
construction that will save time, money and worry. The book tells you just what to do, how 
and when to do it. Nothing has been omitted, no detail has been slighted. Every part of 
the automobile, its equipment, accessories, tools, supplies, spare parts necessary, etc., have 
been discussed comprehensively. If you are or intend to become a motorist, or are in 
any way interested in the modern Gasoline Automobile, this is a book you cannot afford to 
be without. Nearly 600 6x9 pages — and more than 500 new and specially made detail il- 
lustrations, as well as many full, page and double page plates, showing all parts of the 
automobile. Including nine large folding plates. Price $2.50 

BALLOONS AND FLYING MACHINES 



MODEL BALLOONS AND FLYING MACHINES. WITH A SHORT ACCOUNT OF 
THE PROGRESS OF AVIATION. By J. H. Alexander. 

This book has been written with a view to assist those who desire to construct a model airship 
or flying machine. It contains five folding plates of working drawings, each sheet containing 
a different sized machine. Much instruction and amusement can be obtained from the making 
and flying of these models. 

A short account of the progress of aviation is included, which will render the book of greater 
interest. Several illustrations of full sized airship and flying machines of the latest types are 
scattered throughout the text. This practical work gives data, working drawings, and details 
which will assist materially those interested in the problems of flight. 127 pages, 45 illustra- 
tions, 5 folding plates. Price $1.50 

BRAZING AND SOLDERING 



BRAZING AND SOLDERING. By James F. Hobart. 

The only book that shows you just how to handle any job of brazing or soldering that comes 
tilong; tells you what mixture to use, how to make a furnace if you need one. Full of 
valuable kinks. The fifth edition of this book has just been published, and to it much 
new matter and a large number of tested formulas for all kinds of solders and fluxes have 
been added. Illustrated 25 cents 

CHARTS 



MODERN SUBMARINE CHART— WITH 200 PARTS NUMBERED AND NAMED. 

A cross-section view, showing clearly and distinctly all the interior of a Submarine of the 
latest type. You get more information from this chart, about the construction and opera- 
tion of a Submarine, than in any other way. No details omitted — everything is accurate 
and to scale. It is absolutely correct in every detail, having been approved by Naval 
Engineers. All the machinery and devices fitted in a modern Submarine Boat are shown, and 
to make the engraving more readily understood all the features are shown in operative form, 
with Officers and Men in the act of performing the duties assigned to them in service con- 
ditions. This CHART IS REALLY AN ENCYCLOPEDIA OF A SUBMARINE. It 
is educational and worth many times its cost. Mailed in a Tube for 25 cents 



CATALOGUE OF GOOD, PRACTICAL BOOKS 

BOX CAR CHART. 

A chart showing the anatomy of a box car, having every part of the car numbered and its 
proper name given in a reference list 20 cents 

GONDOLA CAR CHART. 

A chart showing the anatomy of a gondola car, having every part of the car numbered and 
its proper reference name given in a reference list 20 cents 

PASSENGER CAR CHART. 

A chart showing the anatomy of a passenger car, having every part of the car numbered and 
its proper name given in a reference list 20 cents 

WESTINGHOUSE AIR-BRAKE CHARTS. 

Chart I. — Shows (in colors) the most modern Westinghouse High Speed and Signal Equip- 
ment used on Passenger Engines, Passenger Engine Tenders, and Passenger Cars. Chart 
II. — Shows (in colors) the Standard Westinghouse Equipment for Freight and Switch En- 
gines, Freight and Switch Engine Tenders, and Freight Cars. Price for the set . 50 cents 

TRACTIVE POWER CHART. 

A chart whereby you can find the tractive power or drawbar pull of any locomotive, without 
making a figure. Shows what cylinders are equal, how driving wheels and steam pressure 
affect the power. What sized engine you need to exert a given drawbar pull or anything 
you desire in this line 50 cents 

HORSE POWER CHART. 

Shows the horse power of any stationary engine without calculation. No matter what the 
cylinder diameter of stroke; the steam pressure or cut-off; the revolutions, or whether con- 
densing or non-condensing, it's all there. Easy to use, accurate, and saves time and calcu- 
lations. Especially useful to engineers and designers 50 cents 

BOILER ROOM CHART. By Geo. L. Fowler. 

A Chart — size 14 x 28 inches — showing in isometric perspective the mechanisms belonging 
in a modern boiler room. Water tube boilers, ordinary grates and mechanical stokers, feed 
water heaters and pumps comprise the equipment. The various parts are shown broken or 
removed, so that the internal construction is fully illustrated. Each part is given a reference 
number, and these, with the corresponding name, are given in a glossary printed at the sides. 
This chart is really a dictionary of the boiler room — the names of more than 200 parts being 
given. It is educational — worth many times its cost 25 cents 

CIVIL ENGINEERING 

HENLEY'S ENCYCLOPEDIA OF PRACTICAL ENGINEERING AND ALLIED 

TRADES. Edited by Joseph G. Horner, A. M. I. E. M. 

This set of five volumes contains about 2,500 pages with thousands of illustrations, including 
diagrammatic and sectional drawings with full explanatory details. This work covers the 
entire practice of Civil and Mechanical Engineering. The best known experts in all branches 
of engineering have contributed to these volumes. The Cyclopedia }s admirably well adapted 
to the needs of the beginner and the self-taught practical man, as well as the mechanical en- 
gineer, designer, draftsman, shop superintendent, foreman, and machinist. The work will be 
found a means of advancement to any progressive man. It is encyclopedic in scope, thorough 
and practical in its treatment of technical subjects, simple and clear in its descriptive matter, 
and without unnecessary technicalities or formulae. The articles are as brief as may be and 
yet give a reasonably clear and explicit statement of the subject, and are written by men who 
have had ample practical experience in the matters of which they write. It tells you all you 
want to know about engineering and tells it so simply, so clearly, so concisely, that one cannot 
help but understand. As a work of reference it is without a peer. $6.00 per single volume. 
For complete set of five volumes, price $25.00 

COKE 

COKE— MODERN COKING PRACTICE; INCLUDING THE ANALYSIS OF 
MATERIALS AND PRODUCTS. By T. H. Byrom and J. E. Christopher. 

A handbook for those engaged in Coke manufacture and the recovery of By-products. Fully 
illustrated with folding plates. It has been the aim of the authors, in preparing this book, 
to produce one which shall be of use and benefit to those who are associated with, or inter- 
ested in, the modern developments of the industry. Contents: I. Introductory. II. (Jen- 



CATALOGUE OF GOOD, PRACTICAL BOOKS 

eral Classification of Fuels. III. Coal Washing. IV. The Sampling and Valuation of Coal, 
Coke, etc. V. The Calorific Power of Coal and Coke. VI. Coke Ovens. VII. Coke Ovens, 
continued. VIII. Coke Ovens, continued. IX. Charging and Discharging of Coke Ovens, 
X. Cooling and Condensing Plant. XI. Gas Exhausters. XII. Composition and Analysis 
of Ammoniacal Liquor. XIII. Working-up of Ammoniacal Liquor. XIV. Treatment of 
Waste Gases from Sulphate Plants. XV. Valuation of Ammonium Sulphate. XVI. Direct 
Recovery of Ammonia from Coke Oven Gases. XVII. Surplus Gas from Coke Oven. Use- 
ful Tables. Very fully illustrated. Price $3. 50 net 

COMPRESSED AIR 

COMPRESSED AIR IN ALL ITS APPLICATIONS. By Gardner D. Hiscox. 

This is the most complete book on the subject of Air that has ever been issued, and its thirty- 
five chapters include about every phase of the subject one can think of. It may be called an 
encyclopedia of compressed air. It is written by an expert, who, in its 665 pages, has dealt 
with the subject in a comprehensive manner, no phase of it being omitted. Includes the 
physical properties of air from a vacuum to its highest pressure, its thermodynamics, com- 
pression, transmission and uses as a motive power; in the Operation of Stationary and Port- 
able Machinery, in Mining. Air Tools, Air Lifts, Pumping of Water, Acids, and Oils; the 
Air Blast for Cleaning and Painting, the Sand Blast and its Work, and the Numerous Appli- 
ances in which Compressed Air is a Most Convenient and Economical Transmitter of Power 
for Mechanical Work, Railway Propulsion, Refrigeration, and the Various Uses to which 
Compressed Air has been applied. Includes forty-four tables of the physical properties of 
air, its compression, expansion, and volumes required for various kinds of work, and a list of 
patents on compressed air from 1875 to date. Over 500 illustrations, 5th Edition, revised and 
enlarged. Cloth bound, $5.00. Half Morocco, price $6.50 

CONCRETE 

ORNAMENTAL CONCRETE WITHOUT MOLDS. By A. A. Houghton. 

The process for making ornamental concrete without molds has long been held as a secret, and 
now, for the first time, this process is given to the public. The book reveals the secret and is 
the only book published which explains a simple, practical method whereby the concrete worker 
is enabled, by employing wood and metal templates of different designs, to mold or model in 
concrete any Cornice, Archivolt, Column, Pedestal, Base Cap, Urn or Pier in a monolithic 
form — right upon the job. These may be molded in units or blocks, and then built up to suit the 
specifications, demanded. This work is fully illustrated, with detailed engravings. Price $2.00 

CONCRETE FROM SAND MOLDS. By A. A. Houghton. 

A Practical Work treating on a process which has heretofore been held as a trade secret by 
the few who possessed it, and which will successfully mold every and any class of ornamental 
concrete work. The process of molding concrete with sand molds is of the utmost practical 
value, possessing the manifold advantages of a low cost of molds, the ease and rapidity of 
operation, perfect details to all ornamental designs, density, and increased strength of the 
concrete, perfect curing of the work without attention and the easy removal of the molds re- 
gardless of any undercutting the design may have. 192 pages. Fully illustrated. Price $2.00 

CONCRETE WALL FORMS. By A. A. Houghton. 

A new automatic wall clamp is illustrated with working drawings. Other types of wall 
forms, clamps, separators, etc., are also illustrated and explained 50 cents 

CONCRETE FLOORS AND SIDEWALKS. By A. A. Houghton. 
The molds for molding squares, hexagonal and many other styles of mosaic floor and side- 
walk blocks are fully illustrated and explained 50 cents 

PRACTICAL CONCRETE SILO CONSTRUCTION. By A. A. Houghton. 
Complete working drawings and specifications are given for several styles of concrete silos, 
with illustrations of molds for monolithic and block silos. The tables, data and information 
presented in this book are of the utmost value in planning and constructing all forms of concrete 
silos .... 50 cents 

MOLDING CONCRETE CHIMNEYS, SLATE AND ROOF TILES. By 
A. A. Houghton. 

The manufacture of all types of concrete slate and roof tile is fully treated. Valuable data 
on all forms of reinforced concrete roofs are contained within its pages. The construction of 
concrete chimneys by block and monoiithic systems is fully illustrated and described. A 
number of ornamental designs of chimney construction with molds are shown in this valu- 
able treatise • . . .... 50 cents 



CATALOGUE OF GOOD, PRACTICAL BOOKS 



MOLDING AND CURING ORNAMENTAL CONCRETE^ By A. A. Houghton. 

The proper proportions of cement and aggregates for various finishes, also the methods of 
thoroughly mixing and placing in the molds, are fully treated. An exhaustive treatise on this 
subject that every concrete worker will find of daily use and value 50 cents 

CONCRETE MONUMENTS, MAUSOLEUMS AND BURIAL VAULTS. By A. A. 
Houghton. 

The molding of concrete monuments to imitate the most expensive cut stone is explained in 
this treatise, with working drawings of easily built molds. Cutting inscriptions and designs 
is also fully treated .50 cents 

MOLDING CONCRETE BATH TUBS, AQUARIUMS AND NATATORIUMS. 

By A. A. Houghton. 

Simple molds and instruction are given for molding many styles of concrete bath tubs, 
swimming pools, etc. These molds are easily built and permit rapid and successful 
work 50 cents 

CONCRETE BRIDGES, CULVERTS AND SEWERS. By A. A. Houghton. 

A number of ornamental concrete bridges with illustrations of molds are given. A collapsible 
center or core for bridges, culverts and sewers is fully illustrated with detailed instructions for 
building 50 cents 

CONSTRUCTING CONCRETE PORCHES. By A. A. Houghton. 

A number of designs with working drawings of molds are fully explained so any one can easily 
construct different styles of ornamental concrete porches without the purchase of expensive 
molds 50 cents 

MOLDING CONCRETE FLOWER POTS, BOXES, JARDINIERES, ETC. By 
A. A. Houghton. 

The molds for producing many original designs of flower pots, urns, flower boxes, jardinieres, 
etc., are fully illustrated and explained, so the worker can easily construct and operate 
same 50 cents 

MOLDING CONCRETE FOUNTAINS AND LAWN ORNAMENTS. By 

A. A. Houghton. 

The molding of a number of designs of lawn seats, curbing, hitching posts, pergolas, sun dials 
and other forms of ornamental concrete for the ornamentation of lawns and gardens, is 
fully illustrated and described 50 cents 

CONCRETE FOR THE FARM AND SHOP. By A. A. Houghton. 

The molding of drain tile, tanks, cisterns, fence posts, stable floors, hog and poultry houses 
and all the purposes for which concrete is an invaluable aid to the farmer are numbered 
among the contents of this handy volume 50 cents 

POPULAR HANDBOOK FOR CEMENT AND CONCRETE USERS. By Myron 
H. Lewis, 

This is a concise treatise of the principles and methods employed in the manufacture and use 
of cement in all classes of modern works. The author has brought together in this work all 
the salient matter of interest to the user of concrete and its many diversified products. The 
matter is presented in logical and systematic order, clearly written, fully illustrated and free 
from involved mathematics. Everything of value to the concrete user is given including kinds 
of cement employed in construction, concrete architecture, inspection and testing, water- 
proofing, coloring and painting, rules, tables, working, and cost data. The book comprises 
thirty- three chapters, as follows: 

Introductory. Kinds of Cements and How They are Made. Properties. Testing and 
Requirements of Hydraulic Cement. Concrete and its Properties. Sand, Broken Stone and 
Gravel for Concrete. How to Proportion the Materials. How to Mix and Place Concrete. 
Forms for Concrete Construction. The Architectural and Artistic Possibilities of Concrete. 
Concrete Residences. Mortars, Plasters and Stucco and How to Use Them. The Artistic 
Treatment of Concrete Surfaces. Concrete Building Blocks. The Making of Ornamental 
Concrete. Concrete Pipes, Fences, Posts, Etc. Essential Features and Advantages of Reen- 
forced Concrete. How to Design Reenforced Concrete Beams, Slabs and Columns. Ex- 
planations of the Methods and Principles in Designing Reenforced Concrete Beams and 
Slabs. Systems of Reenforcement Employed. Reenforced Concrete in Factory and Genera] 



CATALOGUE OF GOOD, PRACTICAL BOOKS 

Building Construction. Concrete in Foundation Work. Concrete Retaining Walls, Abut- 
ments, and Bulkheads. Concrete Arches and Arch Bridges. Concrete Beam and Girder 
Bridges. Concrete in Sewerage and Drainage Works. Concrete Tanks, Dams and Reser- 
voirs. Concrete Sidewalks, Curbs and Pavements. Concrete in Railroad Constructions. 
The Utility of Concrete on the Farm. The Waterproofing of Concrete Structure. Grout 
or Liquid Concrete and Its Use. Inspection of Concrete Work. Cost of Concrete Work. 
Some of the special features of the book are: 1. The Attention Paid to the Artistic and 
Architectural Side of Concrete Work. 2. The Authoritative Treatment of the Problem 
of Waterproofing Concrete. 3. An Excellent Summary of the Rules to be Followed in 
Concrete Construction. 4. The Valuable Cost Data and Useful Tables given. A valuable 
Addition to the Library of Every Cement and Concrete User. Price $2.50 

WATERPROOFING CONCRETE. By Myron H. Lewis. 

Modern Methods of Waterproofing Concrete and Other Structures. A condensed statement 
of the Principles, Rules, and Precautions to be Observed in Waterproofing and Damp- 
proofing Structures and Structural Materials. Paper binding. Illustrated. Price. .50 cents 

DICTIONARIES 

STANDARD ELECTRICAL DICTIONARY. By T. O'Conor Sloane. 

An indispensable work to all interested in electrical science. Suitable alike for the student 
and professional. A practical hand-book of reference containing definitions of about 5,000 
distinct words, terms and phrases. The definitions are terse and concise and include every 
term used in electrical science. Recently issued. An entirely new edition. Should be in 
the possession of all who desire to keep abreast with the progress of this branch of science. 
Complete, concise and convenient. 682 pages. 393 illustrations. Price .... $3.00 

DIES— METAL WORK 

DIES: THEIR CONSTRUCTION AND USE FOR THE MODERN WORKING OF 

SHEET METALS. By J. V. Woodworth. 

A most useful book, and one which should be in the hands of all engaged in the press working 
of metals; treating on the Designing, Constructing, and Use of Tools, Fixtures and Devices, 
together with the manner in which they should be used in the Power Press, for the cheap and 
rapid production of the great variety of sheet metal articles now in use. It is designed as a 
guide to the production of sheet metal parts at the minimum of cost with the maximum of 
output. The hardening and tempering of Press tools and the classes of work which may be 
produced to the best advantage by the use of dies in the power press are fully treated. Its 
505 illustrations show dies, press fixtures and sheet metal working devices, the descriptions 
of which are so clear and practical that all metal-working mechanics will be able to understand 
how to design, construct and use them. Many of the dies and press fixtures treated were 
either constructed by the author or under his supervision. Others were built by skilful 
mechanics and are in use in large sheet metal establishments and machine shops. Price $3.00 

PUNCHES, DIES AND TOOLS FOR MANUFACTURING IN PRESSES. By J. V. 

Woodworth. 

This work is a companion volume to the author's elementary work entitled "Dies, Their 
Construction and Use." It does not go into the details of die making to the extent of the 
author's previous book, but gives a comprehensive review of the field of operations carried on 
by presses. A large part of the information given has been drawn from the author's personal 
experience. It might well be termed an Encyclopedia of Die Making, Punch Making, Die 
Sinking, Sheet Metal Working, and Making of Special Tools, Sub-presses, Devices and Mechani- 
cal Combinations for Punching, Cutting, Bending, Forming, Piercing, Drawing, Compressing 
and Assembling Sheet Metal Parts, and also Articles of other Materials in Machine Tools. 
2d Edition. Price $4.00 

DROP FORGING, DIE SINKING AND MACHINE FORMING OF STEEL. By J. V. 

Woodworth. 

This is a practical treatise on Modern Shop Practice, Processes, Methods, Machines, Tools, 
and Details, treating on the Hot and Cold Machine-Forming of Steel and Iron into Finished 
shapes; Together with Tools, Dies, and Machinery involved in the manufacture of Duplicate 



CATALOGUE OF GOOD, PRACTICAL BOOKS 



Forgings and Interchangeable Hot and Cold Pressed Parts from Bar and Sheet Metal. 
This book fills a demand of long standing for information regarding drop forging, die-sinking 
and machine forming of steel and the shop practice involved, as it actually exists in the 
modern drop forging shop. The processes of die-sinking and force-making, which are thor- 
oughly described and illustrated in this admirable work, are rarely to be found explained in 
such a clear and concise manner as is here set forth. The process of die-sinking relates to 
the engraving or sinking of the female or lower dies, such as are used for drop forgings, hot 
and cold machine forging, swedging and the press working of metals. The process of force- 
making relates to the engraving or raising of the male or upper dies used in producing the 
lower dies for the press-forming and machine-forging of duplicate parts of metal. 

In addition to the arts above mentioned the book contains explicit information regarding 
the drop forging and hardening plants, designs, conditions, equipment, drop hammers, 
forging machines, etc., machine forging, hydraulic forging, autogenous welding and shop 
practice. The book contains eleven chapters, and the information contained in these chapters 
is just what will prove most valuable to the forged metal worker. All operations described 
in the work are thoroughly illustrated by means of perspective half-tones and outline sketches 
of the machinery employed. 300 detailed illustrations. Price $2.50 

DRAWING— SKETCHING PAPER 



LINEAR PERSPECTIVE SELF-TAUGHT. By Herman T. C. Kraus. 

This work gives the theory and practice of linear perspective, as used in architectural, engi- 
neering, and mechanical drawings. Persons taking up the study of the subject by themselves 
will be able by the use of the instruction given to readily grasp the subject, and by reason- 
able practice become good perspective draftsmen. The arrangement of the book is good ; 
the plate is on the left-hand, while the descriptive text follows on the opposite page, so as to 
be readily referred to. The drawings are on sufficiently large scale to show the work clearly 
and are plainly figured. The whole work makes a very complete course on perspective draw- 
ing, and will be found of great value to architects, civil and mechanical engineers, patent 
attorneys, art designers, engravers, and draftsmen $2.50 

PRACTICAL PERSPECTIVE. By Richards and Colvin. 

Shows just how to make all kinds of mechanical drawings in the only practical perspective 
isometric. Makes everything plain so that any mechanic can understand a sketch or drawing 
in this way. Saves time in the drawing room, and mistakes in the shops. Contains practical 
examples of various classes of work. 3rd Edition 50 cents 

SELF-TAUGHT MECHANICAL DRAWING AND ELEMENTARY MACHINE 

DESIGN. By F- L. Sylvester, M.E., Draftsman, with additions by Erik Oberg, 

associate editor of "Machinery." 

This is a practical treatise on Mechanical Drawing and Machine Design, comprising the 
first principles of geometric and mechanical drawing, workshop mathematics, mechanics, 
strength of materials and the calculations and design of machine details. The author's 
aim has been to adapt this treatise to the requirements of the practical mechanic and young 
draftsman and to present the matter in as clear and concise a manner as possible. To 
meet the demands of this class of students, practically all the important elements of machine 
design have been dealt with, and in addition algebraic formulas have been explained, and 
the elements of trigonometry treated in the manner best suited to the needs of the prac- 
tical man. The book is divided into 20 chapters, and in arranging the material, mechan- 
ical drawing, pure and simple, has been taken up first, as a thorough understanding of the 
principles of representing objects facilitates the further study of mechanical subjects. This 
is followed by the mathematics necessary for the solution of the problems in machine de- 
sign which are presented later, and a practical introduction to theoretical mechanics and 
the strength of materials. The various elements entering into machine design, such as cams, 
gears, sprocket wheels, cone pulleys, bolts, screws, couplings, clutches, shafting and fly- 
wheels have been treated in such a way as to make possible the use of the work as a text- 
book for a continuous course of study. It is easily comprehended and assimilated even by 
students of limited previous training. 330 pages, 215 engravings. Price. . . . $2.00 

A NEW SKETCHING PAPER. 

A new specially ruled paper to enable you to make sketches or drawings in isometric perspective 
without any figuring or fussing. It is being used for shop details as well as for assembly 
drawings, as it makes one sketch do the work of three, and no workman can help seeing just 
what is wanted. Pads of 40 sheets, 6x9 inches, 25 cents. Pads of 40 sheets, 9x12 inches. 
50 cents; 40 sheets, 12x18, Price $1.00 



6. 



CATALOGUE OF GOOD, PRACTICAL BOOKS 
ELECTRICITY 

ARITHMETIC OF ELECTRICITY. By Prof. T. O 'Conor Sloane. 

A practical treatise on electrical calculations of all kinds reduced to a series of rules, all of the 
simplest forms, and involving only ordinary arithmetic; each rule illustrated by one or more 
practical problems, with detailed solution of each one. This book is classed among the most 
useful works published on the science of electricity covering as it does the mathematics of 
electricity in a manner that will attract the attention of those who are not familiar with alge- 
braical formulas. 20th Edition. 160 pages. Price $1.00 

COMMUTATOR CONSTRUCTION. By Wm. Baxter, Jr. 

The business end of any dynamo or motor of the direct current type is the commutator. This 
book goes into the designing, building, and maintenance of commutators, shows how to locate 
troubles and how to remedy them; everyone who fusses with dynamos needs this. 25 cents 

DYNAMO BUILDING FOR AMATEURS, OR HOW TO CONSTRUCT A FIFTY-WATT 
DYNAMO. By Arthur J. Weed, Member of N. Y. Electrical Society. 

A practical treatise showing in detail the construction of a small dynamo or motor, the entire 
machine work of which can be done on a small foot lathe. Dimensioned working drawings 
are given for each piece of machine work and each operation is clearly described. This 
machine, when used as a dynamo, has an output of fifty watts; when used as a motor it will 
drive a small drill press or lathe. It can be used to drive a sewing machine on any and all 
ordinary work. The book is illustrated with more than sixty original engravings showing 
the actual construction of the different parts. Among the contents are chapters on 1. Fifty 
Watt Dynamo. 2. Side Bearing Rods. 3. Field Punchings. 4. Bearings. 5. Commu- 
tator. 6. Pulley. 7. Brush Holders. 8. Connection Board. 9. Armature Shaft. 10. 
Armature. 11. Armature Winding. 12. Field Winding. 13. Connecting and Starting. 
Price, paper, 50 cents. Cloth $1.00 

ELECTRIC FURNACES AND THEIR INDUSTRIAL APPLICATIONS. By J. Wright 

This is a book which will prove of interest to many classes of people; the manufacturer who 
desires to know what product can be manufactured successfully in the electric furnace, the 
chemist who wishes to post himself on the electro-chemistry, and the student of science who 
merely looks into the subject from curiosity. The book is not so scientific as to be of use 
only to the technologist, nor so unscientific as to suit only the tyro in electro-chemistry; it 
is a practical treatise of what has been done, and of what is being done, both experimentally 
and commercially with the electric furnace. 

In important processes not only are the chemical equations given, but complete thermal data 
are set forth and both the efficiency of the furnace and the cost of the product are worked 
out, thus giving the work a solid commercial value aside from its efficacy as a work of reference. 
The practical features of furnace building are given the space that the subject deserves. The 
forms and refractory materials used in the linings, the arrangement of the connections to the 
electrodes, and other important details are explained. 288 pages. New Revised Edition. 
Fully illustrated. Price $3.00 

ELECTRIC LIGHTING AND HEATING POCKET BOOK. By Sydney F. Walker. 

This book puts in convenient form useful information regarding the apparatus which is likely 
to be attached to the mains of an electrical company. Tables of units and equivalents are 
included and useful electrical laws and formulas are stated. 

One section is devoted to dynamos, motors, transformers and accessory apparatus; another 
to accumulators, another to switchboards and related equipment, a fourth to a description 
of various systems of distribution, a fifth section to a discussion of instruments, both for 
portable use and switchboards; another section deals with electric lamps of various types 
and accessory appliances, and the concluding section is given up to electric heating apparatus. 
In each section a large number of commercial types are described, frequent tables of dimen- 
sions being included. A great deal of detail information of each line of apparatus is given 
and the illustrations shown give a good idea of the general appearance of the apparatus under 
discussion. The book also contains much valuable information for the central station engi- 
neer. 438 pages. 300 engravings. Bound in leather pocket book form. Price . $3.00 

ELECTRIC WIRING, DIAGRAMS AND SWITCHBOARDS. By Newton Harrison. 

\ thoroughly practical treatise covering the subject of Electric Wiring in all its branches, 
including explanations and diagrams which are thoroughly explicit and greatly simplify 
the subject. Practical every-day problems in wiring are presented and the method of 
obtaining intelligent results clearly shown. Only arithmetic is used. Ohm's law is given 



CATALOGUE OF GOOD, PRACTICAL BOOKS 



a simple explanation with reference to wiring for direct and alternating currents. The funda- 
mental principle of drop of potential in circuits is shown with its various applications. The 
simple circuit is developed with the position of mains, feeders and branches; their treat- 
ment as a part of a wiring plan and their employment in house-wiring clearly illustrated 
Some simple facts about testing are included in connection with the wiring. Molding 
and conduit work are given careful consideration; and switchboards are systematically 
treated, built up and illustrated, showing the purpose they serve, for connection with the 
circuits, and to shunt and compound wound machines. The simple principles of switchboard 
construction, the development of the switchboard, the connections of the various instru- 
ments including the lightning arrester, are also plainly set forth. 

Alternating current wiring is treated, with explanations of the power factor, conditions 
calling for various sizes of wire and a simple way of obtaining the sizes for single-phase, two- 
phase and three-phase circuits. This is the only complete work issued showing and telling 
you what you should know about direct and alternating current wiring. It is a ready refer- 
ence. The work is free from advanced technicalities and 'mathematics, arithmetic being used 
throughout. It is in every respect a handy, well-written, instructive, comprehensive 
volume on wiring for the wireman, foreman, contractor, or electrician. 272 pages ; 1051 illus- 
trations. Price $1.50 

ELECTRIC TOY MAKING, DYNAMO BUILDING, AND ELECTRIC MOTOR CON- 
STRUCTION. By Prof. T. O'Conor Sloane. 

This work treats of the making at home of electrical toys, electrical apparatus, motors, dynamos 
and instruments in general, and is designed to bring within the reach of young and old the 
manufacture of genuine and useful electrical appliances. The work is especially designed for 
amateurs and young folks. 

Thousands of our young people are daily experimenting, and busily engaged in making electrical 
toys and apparatus of various kinds. The present work is just what is wanted to give the 
much needed information in a plain, practical manner, with illustrations to make easy the 
carrying out of the work. 19th Edition. Price $1.00 

ELECTRICIAN'S HANDY BOOK. By Prof. T. O'Conor Sloane. 

This work of 768 pages is intended for the practical electrician who has to make things go. 
The entire field of electricity 'is covered within its pages. Among some of the subjects treated 
are: The Theory of the Electric Current and Circuit, Electro-Chemistry, Primary Batteries, 
Storage Batteries, Generation and Utilization of Electric Powers, Alternating Current, Arma- 
ture Winding, Dynamos and Motors, Motor Generators, Operation of the Central Station 
Switchboards, Safety Appliances, Distribution 'of Electric Light and Power, Street Mains, 
Transformers, Arc and Incandescent Lighting, Electric Measurements, Photometry, Electric 
Railways, Telephony, Bell-Wiring, Electro-Plating, Electric Heating, Wireless Telegraphy, etc. 
It contains no useless theory; everything is to the point. It teaches you just what you want 
to know about electricity. It is the standard work published on the subject. Forty-one 
chapters, 610 engravings, handsomely bound in red leather with title and edges in gold. Price: 

$3.50 

ELECTRICITY IN FACTORIES AND WORKSHOPS, ITS COST AND CONVENIENCE. 
By Arthur P. Haslam. 

A practical book for power producers and power users showing what a convenience the electric 
motor, in its various forms, has become to the modern manufacturer. It also deals with the 
conditions which determine the cost of electric driving, and compares this with other methods 
of producing and utilizing power. 

Among the chapters contained in the book are: The Direct Current Motor; The Alternating 
Current Motor; The Starting and Speed Regulation of Electric Motors; The Rating and 
Efficiency of Electric Motors; The Cost of Energy as Affected by Conditions of Working, The 
Question for the Small Power User; Independent Generating Plants; Oil and Gas Engine 
Plants; Steam Plants; Power Station Tariffs; The Use of Electric Power in Textile Factories; 
Electric Power in Printing Works; The Use of Electric Power in Engineering Workshops 
Miscellaneous Application of Electric Power; The Installation of Electric Motors; The Lighting 
of Industrial Establishments. 312 pages. Very fully illustrated. Price .... $2.50 

ELECTRICITY SIMPLIFIED. By Prof. T. O'Conor Sloane. 

The object of " Electricity Simplified " is to make the subject as plain as possible and to show 
what the modern conception of electricity is; to show how two plates of different metals 
immersed in acid can send a message around the globe; to explain how a bundle of copper wire 
rotated by a steam engine can be the agent in lighting our streets, to tell what the volt, ohm 
and ampere are, and what high and low tension mean; and to answer the questions that 
perpetually arise in the mind in this age of electricity. 172 pages. Illustrated. Price $ 1.00 



CATALOGUE OF GOOD, PRACTICAL BOOKS 



HOUSE WIRING. By Thomas W. Poppe. 

This work describes and illustrates the actual installation of Electric Light "Wiring, the manner 
in which the work should be done, and the method of doing it. The book can be conveniently 
carried in the pocket. It is intended for the Electrician, Helper and Apprentice. It 
solves all Wiring Problems, and contains nothing that conflicts with the rulings of the Nation- 
al Board of Fire Underwriters. It gives just the information essential to the Successful 
"Wiring of a Building. Among the subjects treated are: Locating the Meter. Panel Boards. 
Switches. Plug Receptacles. Brackets. Ceiling Fixtures. The Meter Connections. The 
Feed Wires. The Steel Armored Cable System. The Flexible Steel Conduit System. The 
Ridig Conduit System. A digest of the National Board of Fire Underwriters' rules relating 
to metallic wiring systems. Various switching arrangements explained and diagrammed. 
The easiest method of testing the Three and Four-way circuits explained. The grounding 
of all metallic wiring systems and the reason for doing so shown and explained. The in- 
sulation of the metal parts of lamp fixtures and the reason for the same described and 
illustrated. 125 pages. Fully illustrated. Flexible cloth. Price 50 cents 

HOW TO BECOME A SUCCESSFUL ELECTRICIAN- By Prof. T. O 'Conor Sloaxe. 

Every young man who wishes to become a successful electrician should read this book. It telis 
in simple language the surest and easiest way to become a successful electrician. The studies 
to be followed, methods of work, field of operation and the requirements of the successful 
electrician are pointed out and fully explained. Every young engineer will find this an ex- 
cellent stepping-stone to more advanced works on electricity which he must master before 
success can be attained. Many young men become discouraged at the very outstart by 
attempting to read and study books that are far beyond their comprehension. This book 
serves as the connecting link between the rudiments taught in the public schools and the real 
studv of electricit}\ It is interesting from cover to cover. Fifteenth edition. 202 pages. 
Illustrated. Price $1.00 

MANAGEMENT OF DYNAMOS. By Lummis-Patersox. 

A handbook of theory and practice. This work is arranged in three parts. The first part 
covers the elementary theory of the dynamo. The second part, the construction and action 
of the different classes of dynamos in common use are described; while the third part relates 
to such matters as affect the practical management and working of dynamos and motors. 
The following chapters are contained in the book: Electrical Units; Magnetic Principles; 
Theory of the Dynamo; Armature; Armature in Practice; Field Magnets; Field Magnets in 
Practice; Regulating Dynamos; Coupling Dynamos; Installation, Running, and Maintenance 
of Dynamos; Faults in Dynamos; Faults in Armatures; Motors. 292 pages. 117 illustra- 
tions. Price $1.50 

STANDARD ELECTRICAL DICTIONARY. By T. O'Coxor Sloaxe. 

An indispensable work to all interested in electrical science. Suitable alike for the student 
and professional. A practical hand-book of reference containing definitions of about 5,000 
distinct words, terms and phrases. The definitions are terse and concise and include every 
term used in electrical science. Recently issued. An entirely new edition. Should be in the 
possession of all who desire to keep abreast with the progesss of this branch of science. In 
its arrangement and typography the book is very convenient. The word or term defined is 
printed in black-faced type which readily catches the eye, while the body of the page is in 
smaller but distinct type. The definitions are well worded, and so as to be understood by 
the non-technical reader. The general plan seems to be to give an exact, concise definition, 
and then amplify and explain in a more popular way. Synonyms are also given, and refer- 
ences to other words and phrases are made. A very complete and accurate index of fifty 
pages is at the end of the volume; and as this index contains all synonyms, and as all phrases 
are indexed in every reasonable combination of words, reference to the proper place in the 
body of the book is readily made. It is difficult to decide how far a book of this character 
is to keep the dictionary form, and to what extent it may assume the encyclopedia form. 
For some purposes, concise, exactly worded definitions are needed; for other purposes, more 
extended descriptions are required. This book seeks to satisfy both demands, and does it 
with considerable success. Complete, concise, and convenient. 682 pages. 393 illustra- 
tions. Twelfth edition. Price $3.00 

SWITCHBOARDS. By William Baxter, Jr. 

This book appeals to every engineer and electrician who wants to know the practical side of 
things. It takes up all sorts and conditions of dynamos, connections and circuits and shows 
by diagram and illustration just how the switchboard should be connected. Includes direct 
and alternating current boards, also those for arc lighting, incandescent, and power circuits. 
Special treatment on high voltage boards for power transmission. 2d Edition. 190 pages. 
Illustrated. Price $1.50 

II 



CATALOGUE OF GOOD, PRACTICAL BOOKS 

TELEPHONE CONSTRUCTION, INSTALLATION, WIRING, OPERATION AND 
MAINTENANCE. By W. H. Radcliffe and H. C. Cushing. 

This book gives the principles of construction gnd operation of both the Bell and Independent 
instruments ; approved methods of installing and wiring them ; the means of protecting them 
from lightning and abnormal currents; their connection together for operation as series or 
bridging stations ; and rules for their inspection and maintenance. Line wiring and the wir- 
ing and operation of special telephone systems are also treated. 

Intricate mathematics are avoided, and all apparatus, circuits and systems are thoroughly 
described. The appendix contains definitions of units and terms used in the text. Selected 
wiring tables, which are very helpful, are also included. Among the subjects treated are 
Construction, Operation, and installation of Telephone Instruments, Inspection and Main- 
tenance of Telephone Instruments; Telephone Line Wiring; Testing Telephone Line Wires 
and Cables; Wiring and Operation of Special Telephone Systems, etc. 100 pages, 125 illus- 
trations $1.00 

WIRELESS TELEGRAPHY AND TELEPHONY SIMPLY EXPLAINED. 

By Alfred P. Morgan. 

This is undoubtedly one of the most complete and comprehensible treatises on the subject 
ever published, and a close study of its pages will enable one to master all the details of the 
wireless transmission of messages. The author has filled a long felt want and has succeeded 
in furnishing a lucid, comprehensible explanation in simple language of the theory and 
practice of wireless telegraphy and telephony. 

Among the contents are: Introductory; Wireless Transmission and Reception — The 
Aerial System, Earth Connections — The Transmitting Apparatus, Spark Coils and Trans- 
formers, Condensers, Helixes, Spark Gaps, Anchor Gaps, Aerial Switches— The Receiving 
Apparatus, Detectors, etc. — Tuning and Coupling, Tuning Coils, Loose Couplers, Variable 
Condensers, Directive Wave Systems — Miscellaneous Apparatus, Telephone Receivers, 
Range of Stations, Static, Interference — Wireless Telephones,. Sound and Sound Waves, The 
Vocal Cords and Ear — Wireless Telephones, How Sounds are changed into Electric Waves — 
Wireless Telephones, The Apparatus — Summary. 200 pages. 150 engravings. Price $1.00 

WIRELESS TELEPHONES AND HOW THEY WORK. By James Erskine-Murray. 

This work is free from elaborate details and aims at giving a clear survey of the way in which 
Wireless Telephones work. It is intended for amateur workers and for those whose knowledge 
of electricity is slight. Chapters contained: How We Hear; Historical; The Conversion of 
Sound into Electric Waves; Wireless Transmission; The Production of Alternating Currents 
of High Frequency; How the Electric Waves are Radiated and Received; The Receiving 
Instruments; Detectors; Achievements and Expectations; Glossary of Technical Words, 
Cloth. Price $1.00 

WIRING A HOUSE. By Herbert Pratt. 

Shows a house already built; tells just how to start about wiring it; where to begin; what 
wire to use; how to run it according to Insurance Rules; in fact just the information you need. 
Directions apply equally to a shop. Fourth edition 25 cents 

FACTORY MANAGEMENT, ETC. 

MODERN MACHINE SHOP CONSTRUCTION, EQUIPMENT AND MANAGEMENT. 

By O. E. Perrigo, M.E. 

The only work published that describes the modern machine shop or manufacturing plant from 
the time the grass is growing on the site intended for it until the finished product is shipped. 
By a careful study of its thirty-two chapters the practical man may economically build, 
efficiently equip, and successfully manage the modern machine shop or manufacturing estab- 
ishment. Just the book needed by those contemplating the erection of modern shop buildings, 
the re-building and re-organization of old ones, or the introduction of modern shop methods, 
time and cost system. It is a book written and illustrated by a practical shop man for practical 
shop men who are too busy to read theories and want facts. It is the most complete all around 
book of its kind ever published. It is a practical book for practical men, from the apprentice 
in the shop to the president in the office. It minutely describes and illustrates the most simple 
and yet the most efficient time and cost system yet devised. Price $5.00 

12 



CATALOGUE OF GOOD, PRACTICAL BOOKS 
FUEL 

COMBUSTION OF COAL AND THE PREVENTION OF SMOKE. By Wm. M. Barr. 
This book has been prepared with special reference to the generation of heat by the combus- 
tion of the common fuels found in the United States, and deals particularly with the condi- 
tions necessary to the economic and smokeless combustion of bituminous coals in Stationary 
and Locomotive Steam Boilers. 

The presentation of this important subject is systematic and progressive. The arrangement 
of the book is in a series of practical questions to which are appended accurate answers, 
which describe in language, free from technicalities, the several processes involved in the 
furnace combustion of American fuels ; it clearly states the essential requisites for perfect 
combustion, and points out the best methods for furnace construction for obtaining the great- 
est quantity of heat from any given quality of coal. Nearly 350 pages, fully illustrated. 
Price i| $1.00 

SMOKE PREVENTION AND FUEL ECONOMY. By Booth and Kershaw. 

A complete treatise for all interested in smoke prevention and combustion, being based on 
the German work of Ernst Schmatolla, but it is more than a mere translation of the German 
treatise, much being added. The authors show as briefly as possible the principles of fuel 
combustion, the methods which have been and are at present in use, as well as the proper 
scientific methods for obtaining all the energy in the coal and burning it without smoke. 
Considerable space is also given to the examination of the waste gases, and several of the 
representative English and American mechanical stoker and similar appliances are described. 
The losses carried away in the waste gases are thoroughly analyzed and discussed in the Ap- 

Eendix, and abstracts are also here given of various patents on combustion apparatus. Tne 
ook is complete and contains much of value to all who have charge of large plants. 194 
Illustrated. Price $2.50 



GAS ENGINES AND GAS 

GASOLINE ENGINES : THEIR OPERATION, USE AND CARE. By A. Hyatt 

Verrill. 

The Simplest, Latest and Most Comprehensive popular work published on Gasoline Engines 
describing what the Gasoline engine is ; its construction and operation ; how to install it ; 
how to select it; how to use it and how to remedy troubles encountered. Intended for owners, 
Operators and Users of Gasoline Motors of all kinds. This work fully describes and illus- 
trates the various types of Gasoline engines used in Motor Boats, Motor Vehicles and 
Stationary Work. The parts, accessories and Appliances are described, with chapters on 
ignition, fuel, lubrication, operation and engine troubles. Special attention is given to the 
care, operation and repair of motors with useful hints and suggestions on emergency re- 
pairs and make-shifts. A complete glossary of technical terms and an alphabetically ar- 
ranged table of troubles and their symptoms form most valuable and unique features of this 
manual. Nearly every illustration in the book is original, having been made by the author. 
Every page is full of interest and value. A book which you cannot afford to be without. 320 
pages. Nearly 150 specially made engravings. Price $1.50 

GAS, GASOLINE, AND OIL ENGINES. By Gardner D. Hiscox. 

Just issued, 20th revised and enlarged edition. Every user of a gas engine needs this book. 
Simple, instructive, and right up-to-date. The only complete work on the subject. Tells 
all about the running and management of gas, gasoline and oil engines, as designed and manu- 
factured in the United States. Explosive motors for stationary, marine and vehicle power are 
fully treated, together with illustrations of their parts and tabulated sizes, also their care and 
running are included. Electric ignition by induction coil and jump spark are fully explained 
and illustrated, including valuable information on the testing for economy and power and the 
erection of power plants. 

The rules and regulations of the Board of Fire Underwriters in regard to the installation and 
management of gasoline motors is given in full, suggesting the safe installation of explosive 
motor power.i A list of United States Patents issued on gas, gasoline, and oil engines and their 
adjuncts from 1875 to date is included. 484 pages. 410 engravings Price . . . $2.50 

MODERN GAS ENGINES AND PRODUCER GAS PLANTS. By R. E. Mathot, M.E. 

A guide for the gas engine designer, user, and engineer in the construction, selection, purchase 
installation, operation, and maintenance of gas engines. More than one book on gas engines 
has been written, but not one has thus far even encroached on the field covered by this book. 
Above all Mr. Mathot's work is a practical guide. Recognizing the need of a volume that 

13 



CATALOGUE OF GOOD, PRACTICAL BOOKS 

would assist the gas engine user in understanding thoroughly the motor upon which he depends 
for power, the author has discussed his subject without the help of any mathematics and 
without elaborate theoretical explanations. Every part of the gas engine is described in detail, 
tersely, clearly, with a thorough understanding of the requirements of the mechanic. Helpful 
suggestions as" to the purchase of an engine, its installation, care, and operation form a most 
valuable feature of the work. 320 pages. 175 detailed illustrations. Price . . . $2.50 

uAS ENGINE CONSTRUCTION, OR HOW TO BUILD A HALF-HORSE-POWER 

GAS ENGINE. By Parsell and Weed. 

A practical treatise of 300 pages describing the theory and principles of the action of Gas 
Engines of various types and the design and construction of a half-horse power Gas Engine, with 
illustrations of the work in actual progress, together with the dimensioned working drawings 
giving clearly the sizes of the various details; for the student, the scientific investigator and the 
amateur mechanic. 

Tnis book treats of the subject more from the standpoint of practice than that of theory. The 
principles of operation of Gas Engines are clearly and simply described and then the actual 
construction of a half-horse power engine is taken up, step by step, showing in detail the making 
of the Gas Engine. 3d Edition. 300 pages. Price $2.50 

THE GASOLINE ENGINE ON THE FARM: ITS OPERATION, REPAIR 

AND USES. By Xeno W. Putnam. 

This is a practical treatise on the Gasoline and Kerosene engine intended for the man who 
wants to know just how to manage his engine and how to apply it to all kinds of farm work 
to the best advantage. 

The book includes selecting the most suitable engine for farm work, its most convenient and 
efficient installation, with chapters on troubles, their remedies and how to avoid them. 
The care and management of the farm tractor in plowing, harrowing, harvesting and road 
grading are fully covered; also plain directions are given for handling the tractor on the road. 
Special attention is given to relieving farm life of its drudgery by applying power to the 
disagreeable small tasks which must otherwise be done by hand. Many homemade con- 
trivances for cutting wood, supplying kitchen, garden and barn with water, loading, hauling 
and unloading hay, delivering grain to the bins or the feed. trough are included; also full 
directions for making the engine milk the cows, churn, wash, sweep the house and clean the 
windows, etc. Very fully illustrated with drawings of working parts and cuts showing 
Stationary, Portable and Tractor Engines doing all kinds of farm work. 300 pages. Nearly 
150 engravings. 12mo. Price $1.50 

CHEMISTRY OF GAS MANUFACTURE. By H. M. Royles. 

This book covers points likely to arise in the ordinary course of the duties of the engineer or 
manager of a gas works not large enough to necessitate the employment of a separate chemical 
staff. It treats of the testing of the raw materials employed in the manufacture of illuminat- 
ing coal gas, and of the gas produced. The preparation of standard solutions is given as well 
as the chemical and physical examination of gas coal including among its contents — Prepa- 
rations of Standard Solutions, Coal, Furnaces, Testing and Regulation. Products of Car- 
bonization. Analysis of Crude Coal Gas. Analysis of Lime. Ammonia. Analysis of Oxide 
of Iron. Naphthalene. Analysis of Fire-Bricks and Fire-Clay. Weldom and Spent Oxide. 
Photometry and Gas Testing. Carburetted Water Gas. Metrooolis Gas. Miscellaneous 
Extracts. Useful Tables $4.50 

GEARING AND CAMS 

BEVEL GEAR TABLES. By D. Ag. Engstrom. 

A book that will at once commend itself to mechanics and draftsmen. Does away with all 
the trigonometry and fancy figuring on bevel gears and makes it easy for anyone to lay them 
out or make them just right. There are 36 full-page tables that show every necessary dimen- 
sion for all sizes or combinations you're apt to need. No puzzling figuring or guessing. 
Gives placing distance, all the angles (including cutting angles), and the correct cutter to use. 
A copy of this prepares you for anything in the bevel gear line. 66 pages. . $1.00 

CHANGE GEAR DEVICES. By Oscar E. Perrigo. 

A practical book for every designer, draftsman, and mechanic interested in the invention and 
development of the devices for feed changes on the different machines requiring such mechan- 
ism. All the necessary information on this subject is taken up, analyzed, classified, sifted, 
and concentrated for the use of busy men who have not the time to go through the masses 
of irrelevant matter with which such a subject is usually encumbered and select such infor- 
mation as will be useful to them. 

It shows just what has been done, how it has been done, when it was done, and who did it. 
It saves time in hunting up patent records and re-inventing old ideas. 88 pages. $1.00 

14 



CATALOGUE OF GOOD, PRACTICAL BOOKS 



DRAFTING OF CAMS. By Louis Rouillion. 

problem unless you 
any kind of cam yo 

HYDRAULICS 



The laying out of cams is a serious problem unless you know how to go at it right. This puts 
you on the right road for practically any kind of cam you are likely to run up against. 25 cents 



HYDRAULIC ENGINEERING. By Gardner D. Hiscox. 

A treatise on the properties, power, and resources of water for all purposes. Including the 
measurement of streams, the flow of water in pipes or conduits; the horse-power of falling 
water; turbine and impact water-wheels, wave motors, centrifugal, reciprocating, and air- 
lift pumps. With 300 figures and diagrams and 36 practical tables. 

All who are interested in water-works development will find this book a useful one, because 
it is an entirely practical treatise upon a subject of present importance, and cannot fail in 
having a far-reaching influence, and for this reason should have a place in the working library 
of every engineer. Among the subjects treated are: Historical — Hydraulics, Properties of 
Water ; Measurement of the flow of Streams ; Flow from Subsurface orifices and nozzles ; 
Flow of water in Pipes; Siphons of various kinds; Dams and Great Storage Reservoirs; 
City and Town Water Supply; Wells and their reenforcement ; Air lift methods of raising 
water ; artesian wells ; Irrigation of Arid districts ; Water Power, Water Wheels ; Pumps and 
Pumping Machinery; Reciprocating Pumps; Hydraulic Power Transmission; Hydraulic 
Mining; Canals; Ditches; Conduits and Pipe Lines; Marine Hydraulics; Tidal and Sea 
Wave power, etc. 320 pages. Price $4.00 

ICE AND REFRIGERATION 



POCKET BOOK OF REFRIGERATION AND ICE MAKING. By A. J. Wallis- 
Taylor. 

This is one of the latest and most comprehensive reference books published on the subject of 
refrigeration and cold storage. It explains the properties and refrigerating effect of the different 
fluids in use, the management of refrigerating machinery and the construction and insulation 
of cold rooms with their required pipe surface for different degrees of cold ; freezing mixtures 
and non-freezing brines, temperatures of cold rooms for all kinds of provisions, cold storage 
charges for all classes of goods, ice making and storage of ice, data and memoranda for constant 
reference by refrigerating engineers, with nearly one hundred tables containing valuable 
references to every fact and condition required in the installment and operation of a refrigerat- 
ing plant. Illustrated. (5th Edition, revised.) Price $1.50 

INVENTIONS— PATENTS 

INVENTOR'S MANUAL, HOW TO MAKE A PATENT PAY. 

This is a book designed as a guide to inventors in perfecting their inventions, taking out their 
patents and disposing of them. It is not in any sense a Patent Solicitor's Circular, nor a 
Patent Broker's Advertisement. No advertisements of any description appear in the work. 
It is a book containing a quarter of a century's experience of a successful inventor, together 
with notes based upon the experience of many other inventors. 

Among the subjects treated in this work are: How to Invent. How to Secure a Good 
Patent. Value of Good Invention. How to exhibit an Invention. How to Interest 
Capital. How to Estimate the Value of a Patent. Value of Design Patents. Value of 
Foreign Patents. Value of Small Inventions. Advice on Selling Patents. Advice on the 
Formation of Stock Companies. Advice on the Formation of Limited Liability Companies. 
Advice on Disposing of Old Patents. Advice as to Patent Attorneys. Advice as to Selling 
Agents. Forms of Assignments. License and Contracts. State Laws Concerning Patent 
Rights. 1900 Census of the United States by counties of over 10,000 population. Revised 
edition. 120 pages. Price. $1.00 

KNOTS 

KNOTS, SPLICES AND ROPE WORK. By A. Hyatt Verrill. 

This is a practical book giving complete and simple directions for making all the most use- 
ful and ornamental knots in common use. with chapters on Splicing, Pointing, Seizing, 

x 5 



CATALOGUE OF GOOD, PRACTICAL BOOKS 

Serving, etc. This book is fully illustrated with one hundred and fifty original engravings, 
which show how each knot, tie or splice is formed and its appearance when finished. The 
book will be found of the greatest value to Campers, Yachtsmen, Travelers, Boy Scouts, 
in fact to anyone having occasion to use or handle rope or knots for any purpose. The book 
is thoroughly reliable and practical and is not only a guide but a teacher. It is the standard 
work on the subject. Among the contents are: 1. Cordage, Kinds of Rope. Construction 
of Rope, Parts of Rope Cable and Bolt Rope. Strength of Rope, Weight of Rope. 2. Sim- 
ple knots and Bends. Terms used in Handling Rope. Seizing Rope. 3. Ties and Hitches. 
4. Noose, Loops and Mooring Knots. 5. Shortenings, Grommets and Selvages. 6. Lash- 
ings. Seizings and Splices. 7. Fancy Knots and Rope Work. 128 pages. 150 original 
engravings. Price 60 cents 

LATHE WORK 

MODERN AMERICAN LATHE PRACTICE. By Oscar E. Perrigo. 

This is a new book from cover to cover, and the only complete American work on the subject 
written by a man who knows not only how work ought to be done, but who also knows 
how to do it, and how to convey this knowledge to others. It is strictly up-to-date in its 
descriptions and illustrations, which represent the very latest practice in lathe and boring 
mill operations as well as the construction of and latest developments in the manufacture 
of these important classes of machine tools. 

Lathe history and the relations of the Lathe to manufacturing are given ; also a description 
of the various devices for Feeds and Thread Cutting mechanisms from early efforts in this 
direction to the present time. Lathe design is thoroughly discussed, including Back Gearing, 
Driving Cones, Thread Cutting Gears, and all the essential elements of the modern Lathe. 
The classification of Lathes is taken up, giving the essential differences of the several types 
of Lathes, including, as is usually understood, Engine Lathes, Bench Lathes, Speed Lathes, 
Forge Lathes, Gap Lathes, Pulley Lathes, Forming Lathes, Multiple Spindle Lathes, Rapid 
Reduction Lathes, Precision Lathes, Turret Lathes, Special Lathes, Electrically Driven 
Lathes, etc. 424 pages. 314 illustrations. Price $2.50 

PRACTICAL METAL TURNING. By Joseph G. Horner. 

This important and practical subject is treated in a full and exhaustive manner and nothing 
of importance is omitted. The principles and practice and all the different branches of Turn- 
ing are considered and well illustrated. All the different kinds of Chucks of usual forms, as 
well as some unusual kinds, are shown. A feature of the book is the important section de- 
voted to modern Turret practice; Boring is another subject which is treated fully; and the 
chapter on Tool Holders illustrates a large number of representative types. Thread Cutting 
is treated at reasonable length; and the last chapter contains a good deal of information 
relating to the High-Speed Steels and their work. The numerous tools used by machinists 
are illustrated, and also the adjuncts of the lathe. In fact, the entire subject is treated in 
such a thorough manner as to make this book the standard one on Ihe subject. It is indis- 
pensable to the manager, engineer, and machinist as well as to the student, amateur, and 
experimental, man who desires to keep up-to-date. 400 pages, fully illustrated. Price $3.50 

TURNING AND BORING TAPERS. By Fred H. Colvin. 

There are two ways to turn tapers; the right way and one other. This treatise has to do with 
the right way; it tells you how to start the work properly, how to set the lathe, what tools to 
use and how to use them, and forty and one other little things that y >u should know. Fourth 
edition 25 cents 

LIQUID AIR 

LIQUID AIR AND THE LIQUEFACTION OF GASES. By T. O'Conor Sloane. 

This book gives the history of the theory, discovery, and manufacture of Liquid Air, and 

contains an illustrated description of all the experiments that have excited the wonder of 

audiences all over the country. It shows how liquid air, like water, is carried hundreds of 

miles and is handled in open buckets. It tells what may be expected from it in the near 

future. 

A book that renders simple one of the most perplexing chemical problems of the century. 

Startling developments illustrated by actual experiments. 

It is not only a work of scientific interest and authority, but is intended for the general reader. 

Deing written in a popular style — easily understood by every one. Second edition. 365 

pages. Price $2.00 

16 



CATALOGUE OF GOOD, PRACTICAL BOOKS 
LOCOMOTIVE ENGINEERING 

AIR-BRAKE CATECHISM. By Robert H. Blackall. 

This book is a standard text book. It covers the Westinghouse Air-Brake Equipment, In- 
cluding the No. 5 and the No. 6 E. T Locomotive Brake Equipment; the K (Quick-Service) 
Triple Valve for Freight Service; and the Cross-Compound Pump. The operation of all parts 
of the apparatus is explained in detail, and a practical way of finding their peculiarities and 
defects, with a proper remedy, is given. It contains 2,000 questions with their answers, 
which will enable any railroad man to pass any examination on the subject of Air Brakes. 
Endorsed and used by air-brake instructors and examiners on nearly every railroad in the 
United States. 25th Edition. 350 pages, fully illustrated with folding] plates and dia- 
grams $2.00 

AMERICAN COMPOUND LOCOMOTIVES. By Fred. H. Colvin. 

The only book on compounds for the engineman or shopman that shows in a plain, practical 
way the various features of compound locomotives in use. Shows how they are made, what 
to do when they break down or balk. Contains sections as follows: — A Bit of History. The- 
ory of Compounding Steam Cylinders. Baldwin Two-Cylinder Compound. Pittsburg Two- 
Cylinder Compound. Rhode Island Compound. Richmond Compound. Rogers Compound. 
Schenectady Two-Cylinder Compound. Vauclain Compound. Tandem Compounds. Bald- 
win Tandem. The Colvin- Wight man Tandem. Schenectady Tandem. Balanced Loco- 
motives. Baldwin Balanced Compound. Plans for Balancing. Locating Blows. Break- 
downs. Reducing Valves. Drifting. Valve Motion. Disconnecting. Power of Compound 
Locomotives. Practical Notes. 

Fully illustrated Fand containing ten special "Duotone" inserts on heavy Plate Paper, show- 
ing different types of Compounds. 142 pages. Price $1.00 

APPLICATION OF HIGHLY SUPERHEATED STEAM TO LOCOMOTIVES. By 

Robert Garbe. 

A practical book. Contains special chapters on Generation of Highly Superheated Steam; 
Superheated Steam and the Two-Cylinder Simple Engine; Compounding and Superheating; 
Designs of J Locomotive Superheaters; Constructive Details of Locomotives using Highly 
Superheated Steam; Experimental and Working Results. Illustrated with folding plates 
and tables. Price $2.50 

COMBUSTION OF COAL AND^ THE PREVENTION OF SMOKE. 
By Wm. M. Barr. 

This book has been prepared with special reference to the generation of heat by the combus- 
tion of the common fuels found in the United. States, and deals particularly with the condi- 
tions necessary to the economic and smokeless combustion of bituminous coal in Stationary 
and Locomotive Steam Boilers. 

The presentation of this important subject is systematic and progressive. The arrangement 
of the book is in a series of practical questions to which are appended accurate answers, 
which describe in language, free from technicalities, the several processes involved in the 
furnace combustion of American fuels; it clearly states the essential requisites for perfect 
combustion, and points out the best methods of furnace construction for obtaining the 
greatest quantity of heat from any given quality of coal. Nearly 350 pages, fully illustrated. 
Price $1.00 

DIARY OF A ROUND HOUSE FOREMAN. By T. S. Reilly . 

This is the greatest book of railroad experiences ever published. Containing a fund of infor- 
mation and suggestions along the line of handling men, organizing, etc. , that one cannot afford 
to miss. 176 pages. Price $1.00 

LINK MOTIONS, VALVES AND VALVE SETTING. By Fred H. Colvin, Associate 
Editor of "American Machinist." 

A handy book for the engineer or machinist that clears up the mysteries of valve setting. 
Shows the different valve gears in use, how they work, and why. Piston and slide valves 
of different types are illustrated and explained. A book that every railroad man in the mo- 
tive power department ought to have. Contains chapters on Locomotive Link Motion, 
Valve Movements, Setting Slide Valves, Analysis by Diagrams, Modern Practice, Slip of 
Block, Slide Valves, Piston Valves, Setting Piston Valves, Joy-Allen Valve Gear, Walschaert 
Valve Gear, Gooch Valve Gear, Alfree-Hubbell Valve Gear, etc., etc. Fully illustrated. 
Price 50 cents 

*7 



CATALOGUE OF GOOD, PRACTICAL BOOKS 

LOCOMOTIVE BOILER CONSTRUCTION. By Frank A. Kleinhans. 

The construction of boilers in general is treated, and following this, the locomotive boiler 
is taken up in the order in which its various parts go through the shop. Shows all types of 
boilers used: gives details of construction; practical facts, such as life of riveting, punches 
and dies; work done per day, allowance for bending and flanging sheets, and other data. 
Locomotive boilers present more difficulty in laying out and building than any other type, 
and for this reason the author uses them as examples. Anyone who can handle them can 
tackle anything. 

Contains chapters on Laying Out Work; Flanging and Forging; Punching; Shearing: Plate 
Planing; General Tables; Finishing Parts; Bending; Machinery Parts; Riveting; Boiler 
Details; Smoke Box Details; Assembling and Calking; Boiler Shop Machinery, etc., etc. 
There isn't a man who has anything to do with boiler work, either new or repair work, who 
doesn't need this book. The manufacturer, superintendent, foreman, and boiler worker — 
all need it. No matter what the type of boiler, you'll find a mint of information that you 
wouldn't be without. Over 400 pages, five large folding plates. Price $3.00 

LOCOMOTIVE BREAKDOWNS AND THEIR REMEDIES. By Geo. L. Fowler. 
Revised by Wm. W. Wood, Air-Brake Instructor. Just issued. Revised pocket 
edition. 

It is out of the question to try and tell you about every subject that is covered in this pocket 
edition of Locomotive Breakdowns. Just imagine all the common troubles that an engineer 
may expect to happen some time, and then add all of the unexpected ones, troubles that could 
occur, but that you had never thought about, and you will find that they are all treated with 
the very best methods of repair. Walschaert Locomotive Valve Gear Troubles, Electric 
Headlight Troubles, as well as Questions and Answers on the Air Brake are all included. 294 
pages. 7th Revised Edition. Fully illustrated $1.00 

LOCOMOTIVE CATECHISM. By Robert Grimshaw. 

The revised edition of "Locomotive Catechism," by Robert Grimshaw, is a New Book from 
Cover to Cover. It contains twice as many pages and double the number of illustrations 
of previous editions. Includes the greatest amount of practical information ever published 
on the construction and management of modern locomotives. Specially Prepared Chapters 
on the Walschaert Locomotive Valve Gear, the Air Brake Equipment and the Electric Head 
Light are given. 

It commends itself at once to every Engineer and Fireman, and to all who are going in for 
examination or promotion. In plain language, with full complete answers, not only all the 
questions asked by the examining engineer are given, but those which the young and less 
experienced would ask the veteran, and which old hands ask as "stickers." It is a veritable 
Encyclopedia of the Locomotive, is entirely free from mathematics, easily understood and 
thoroughly up-to-date. Contains over 4,000 Examination Questions with their Answers. 
825 pages, 437 illustrations and three folding plates. 28th Revised Edition. . . $2.50 

PRACTICAL INSTRUCTOR AND REFERENCE BOOK FOR LOCOMOTIVE 
FIREMEN AND ENGINEERS. By Chas. F. Lockhart. 

An entirely new book on the Locomotive. It appeals to every railroad man, as it tells him 
how things are done and the right way to do them. Written by a man who has had years 
of practical experience in locomotive shops and on the road firing and running. The infor- 
mation given in this book cannot be found in any other similar treatise. Eight hundred and 
fifty-one questions with their answers are included, which will prove specially helpful to 
those preparing for examination. Practical information on: The Construction and Opera- 
tion of Locomotives. Breakdowns and their Remedies; Air Brakes and Valve Gears. 
Rules and Signals are handled in a thorough manner. As a book of reference it cannot be 
excelled. The book is divided into six parts, as follows: 1. The Fireman's Duties. 2. 
General description of the Locomotive. 3. Breakdowns and their Remedies. 4. Air Brakes. 
5. Extracts from Standard Rules. 6. Questions for examination. The 851 questions have 
been carefully selected and arranged. These cover the examinations required by the different 
railroads. 368 pages. 88 illustrations. Price $1.50 

PREVENTION OF RAILROAD ACCIDENTS, OR SAFETY IN RAILROADING. 

By George Bradshaw. 

This book is a heart-to-heart talk with Railroad Employees, dealing with facts, not theories, 
and showing the men in the ranks, from every-day experience, how accidents occur and how 
they may be avoided. The book is illustrated with seventy original photographs and draw- 
ings showing the safe and unsafe methods of work. No visionary schemes, no ideal pictures. 
Just plain facts and Practical Suggestions are given. Every railroad employee who reads the 

18 



CATALOGUE OF" GOOD, PRACTICAL BOOKS 

book is a better and safer man to have in railroad service. It gives just the information 
which will be the means of preventing many injuries and deaths. All railroad employees 
should procure a copy, read it, and do your part in preventing accidents. 169 pages. Pocket 
Size. Fully illustrated. Price 50 cents 

TRAIN RULE EXAMINATIONS MADE EASY. By G. E. Colling wood. 
This is the only practical work on train-rules in print. Every detail is covered, and puzzling 
points are explained in simple, comprehensive language, making it a practical treatise for 
the Train Dispatcher, Engineman, Trainman, and all others who ha Tr e to do with the move- 
ments of trains. Contains complete and reliable information of the Standard Code of Train 
Rules for single track. Shows Signals in Colors, as used on the different roads. Explains 
fully the practical application of train orders, giving a clear and definite understanding of all 
orders which may be used. The meaning and necessity for certain rules are explained in 
such a manner that the student may know beyond a doubt the rights conferred under any 
orders he may receive or the action required by certain rules. 

As nearly all roads require trainmen to pass regular examinations, a complete set of examina- 
tion questions, with their answers, are included. These will enable the student to pass the 
required examinations with credit to himself and the road for which he works. 256 pages.. 
Fully illustrated with Train Signals in colors. Price $1.26 

TRAIN RULES AND DESPATCHING. By H. A. Dalby. 

Every railroad man, no matter what department he's in, needs a copy of this book. It gives, 
the standard rules for both single and double track, shows all the signals, with colors wher- 
ever necessary, and has a list of towns where time changes, with a map showing the whole 
country. The rules are explained wherever there is any doubt about their meaning or where 
they are modified by different railroads. It's the only practical book on train rules in print. 
Over 220 pages. Leather cover. Price $1.50 

THE WALSCHAERT AND OTHER MODERN RADIAL VALVE GEARS FOR 
LOCOMOTIVES. By Wm. W. Wood. 

If you would thoroughly understand the Walschaert Valve Gear you should possess a copy 
of this book, as the author takes the plainest form of a steam engine — a stationary engine in 
the rough, that will only turn its crank in one direction — and from it builds up — with the 
reader's help — a modern locomotive equipped with the Walschaert Valve Gear, complete. 
The points discussed are clearly illustrated ; two large folding plates that show the positions 
of the valves of both inside or outside admission type, as well as the links and other parts of 
the gear when the crank is at nine different points in its revolution, are especially valuable 
in making the movement clear. These employ sliding cardboard models which are contained 
in a pocket in the cover. 

The book is divided into five general divisions, as follows: I. Analysis of the gear. II. De- 
signing and erecting the gear. III. Advantages of the gear. IV. Questions and answers 
relating to the Walschaert Valve Gear. V. Setting valves with the Walschaert Valve Gear; 
the three primary types of locomotive valve motion; modern radial valve gears other than 
the Walschaert; the Hobart All-free valve and valve gear, with questions and answers on 
breakdowns; the Baker-Pilliod valve gear; the Improved Baker- Pilliod Valve Gear, with 
questions and answers on breakdowns. 

The questions with full answers given will be especially valuable to firemen and engineers 
in preparing for an examination for promotion. 245 pages. Third Revised Edition. 
Price $1.50 

WESTINGHOUSE E— T AIR-BRAKE INSTRUCTION POCKET BOOK. By Wm. 

W. Wood, Air-Brake Instructor. 

Here is a book for the railroad man, and the man who aims to be one. It is without doubt 
the only complete work published on the Westinghouse E-T Locomotive Brake Equipment. 
Written by an Air Brake Instructor who knows just what is needed. It covers the subject 
thoroughly. Everything about the New Westinghouse Engine and Tender Brake Equip- 
ment, including the Standard No. 5 and the Perfected No. 6 Style of brake, is treated in de- 
tail. Written in plain English and profusely illustrated with Colored Plates, which enable 
one to trace the flow of pressures throughout the entire equipment. The best book ever 
published on the Air Brake. Equally good for the beginner and the advanced engineer. 
Will pass any one through any examination. It informs and enlightens you on every point. 
Indispensable to every engineman and trainman. 

Contains examination questions and answers on the E-T equipment. Covering what the 
E-T Brake is. How it should be operated. What to do when defective. Not a question can 
be asked of the engineman up for promotion on either the No. 5 or the No. 6 E-T equipment 
that is not asked and answered in the book. If you want to thoroughly understand the E-T 
equipment get a copy of this book. It covers every detail. Makes Air Brake troubles and 
examinations easy. Price $1.50 

I 9 



CATALOGUE OF GOOD, PRACTICAL BOOKS 



MACHINE SHOP PRACTICE 

AMERICAN TOOL MAKING AND INTERCHANGEABLE MANUFACTURING. By 

J. V. WOODWORTH. 

A "shoppy" book, containing no theorizing, no problematical or experimental devices, there 
are no badly proportioned and impossible diagrams, no catalogue cuts, but a valuable collec- 
tion of drawings and descriptions of devices, the rich fruits of the author's own experience. 
In its 500-odd pages the one subject only, Tool Making, and whatever relates thereto, is 
dealt with. The work stands without a rival. It is a complete practical treatise on the 
art of American Tool Making and system of interchangeable manufacturing as carried on 
to-day in the United States. In it are described and illustrated all of the different types 
and classes of small tools, fixtures, devices, and special appliances which are in general use 
in all machine manufacturing and metal working establishments where economy, capacity, 
and interchangeability in the production of machined metal parts are imperative. The 
science of jig making is exhaustively discussed, and particular attention is paid to drill jigs, 
boring, profiling and milling fixtures and other devices in which the parts to be machined 
are located and fastened within the contrivances. All of the tools, fixtures, and devices 
illustrated and described have been or are used for the actual production of work, such as 
parts of drill presses, lathes, patented machinery, typewriters, electrical apparatus, mechan- 
ical appliances, brass goods, composition parts, mould products, sheet metal articles, drop 
forgings, jewelry, watches, medals, coins, etc. 531 pages. Price $4=00 

HENLEY'S ENCYCLOPEDIA OF PRACTICAL ENGINEERING AND ALLIED 

TRADES. Edited by Joseph G. Horner, A.M. I., M.E. 

This set of five volumes contains about 2,500 pages with thousands of illustrations, including 
diagrammatic and sectional drawings with full explanatory details. This work covers the 
entire practice of Civil and Mechanical Engineering. The best known expert in all branches 
of engineering have contributed to these volumes. The Cyclopedia is admirably well adapted 
to the needs of the beginner and the self-taught practical man, as well as the mechanical en- 
gineer, designer, draftsman, shop superintendent, foreman, and machinist. The work will be 
found a means of advancement to any progressive man. It is encyclopedic in scope, thorough 
and practical in its treatment of technical subjects, simple and clear in its descriptive matter, 
and without unnecessary technicalities or formulae. The articles are as brief as may be and 
yet give a reasonably clear and explicit statement of the subject, and are written by men who 
have had ample practical experience in the matters of which they write. It tells you all you 
want to know about engineering and tells it so simply, so clearly, so concisely, that one cannot 
help but understand. As a work of reference it is without a peer. $6.00 per volume. For 
complete set of five volumes, price $25.00 

MACHINE SHOP ARITHMETIC. By Colvin-Cheney. 

This is an arithmetic of the things you have to do with daily. It tells you plainly about: how 
to find areas of figures; how to find surface or volume of balls or spheres; handy ways for 
calculating; about compound gearing; cutting screw threads on any lathe; drilling for taps; 
speeds of drills, taps, emery wheels, grindstones, milling cutters, etc.; all about the Metric 
system with conversion tables; properties of metals; strength of bolts and nuts; decimal 
equivalent of an inch. All sorts of machine shop figuring and 1,001 other things, any one of 
which ought to be worth more than the price of this book to you, and it saves you the trouble 
of bothering the boss. 6th Edition. 131 pages. Price 50 cents 

MODERN MACHINE SHOP CONSTRUCTION, EQUIPMENT AND MANAGEMENT. 

By Oscar E. Perrigo. 

The only work published that describes the Modern Machine Shop or Manufacturing Plant from 
the time the grass is growing on the site intended for it until the finished product is shipped. 
Just the book needed by those contemplating the erection of modern shop buildings, the re- 
building and reorganization of old ones, or the introduction of Modern Shop Methods, time and 
cost systems. It is a book written and illustrated by a practical shop man for practical shop 
men who are too busy to read theories and want facts. It is the most complete all-around 
book of its kind ever published. 400 large quarto pages. 225 original and specially-made 
illustrations. Price $5.00 

MECHANICAL APPLIANCES, MECHANICAL MOVEMENTS AND NOVELTIES 
OF CONSTRUCTION. By Gardner D. Hiscox. 

This is a supplementary volume to the one upon mechanical movements. Unlike the first 
volume, which is more elementary in character, this volume contains illustrations and descrip- 
tions of many combinations of motions and of mechanical devices and appliances found in 
different lines of machinery. Each device being shown bv a line drawing with a description 

20 



CATALOGUE OF GOOD, PRACTICAL BOOKS 



showing its working parts and the method of operation. From the multitude of devices de- 
scribed, and illustrated, might be mentioned, in passing, such items as conveyors and elevators, 
Prony brakes, thermometers,! various types of boilers, solar engines, oil-fuel burners, condensers, 
evaporators, Corliss and other valve gears, governors, gas engines, water motors of various 
descriptions, air ships, motors and dynamos, automobile and motor bicycles, railway block 
signals, car couplers, link and gear motions, ball bearings, breech block mechanism for heavy 
guns, and a large accumulation of others of equal importance. 1,000 specially made engrav- 
ings. 396 octavo pages. Price $2.50 

MECHANICAL MOVEMENTS, POWERS, AND DEVICES. By Gardner D. Hiscox. 

This is a collection of 1,890 engravings of different mechanical motions and appliances, accom- 
panied by appropriate text, making it a book of great value to the inventor, the draftsman, 
and to all readers with mechanical tastes. The book is divided into eighteen sections or 
chapters in which the subject matter is classified under the following heads: Mechanical Powers; 
Transmission of Power; Measurement of Power, Steam Power; Air Power Appliances; Electric 
Power and Construction, Navigation and Roads; Gearing; Motion and Devices; Controlling 
Motion; Horological; Mining; Mill and Factory Appliances; Construction and Devices; 
Drafting Devices: Miscellaneous Devices, etc. 12th edition, 400 octavo pages. Price $2.50 

MACHINE SHOP TOOLS AND SHOP PRACTICE. By W. H. Vandervoort. 

A work of 555 pages and 673 illustrations, describing in every detail the construction, operation, 
and manipulation of both hand and machine tools. Includes chapters on filing, fitting, and 
scraping surfaces; on drills, reamers, taps, and dies; the lathe and its tools; planers, shapers, 
and their tools; milling machines and cutters; gear cutters and gear cutting; drilling machines 
and drill work; grinding machines and their work; hardening and tempering; gearing, belting 
and transmission machinery: useful data and tables. 6th edition. Price .... $3.00 

THE MODERN MACHINIST. By John T. Usher. 

This is a book showing, by plain description and by profuse engravings, made expressly for 
the work, all that is best, most advanced, and of the highest efficiency in modern machine 
shop practice, tools, and implements, showing the way by which and through which, as Mr. 
Maxim says, "American machinists have become and are the finest mechanics in the world." 
Indicating as it does, in every line, the familiarity of the author with every detail of daily 
experience in the shop, it cannot fail to be of service to any man joractically -connected with 
the shaping or finishing of metals. 

There is nothing experimental or visionary about the book, all devices being in actual use 
and giving good results. It might be called a compendium of shop methods, showing a vari- 
ety of special tools and appliances which will give new ideas to many mechanics, from the 
superintendent down to the man at the bench. It will be found a valuable addition to any 
machinist's library, and should be consulted whenever a new or difficult job is to be done, 
whether it is boring, milling, turning, or planing, as they are all treated in a practical manner. 
Fifth Edition. 320 pages. 250 illustrations. Price ... $2.50 

MODERN MILLING MACHINES: THEIR DESIGN, CONSTRUCTION AND OPERA- 
TION. By Joseph G. Horner. 

This book describes and illustrates the Milling Machine and its work in such a plain, clear, 
and forceful manner, and illustrates the subject so clearly and completely, that the up-to-date 
machinist, student, or mechanical engineer cannot afford to do without the valuable infor- 
mation which it contains. It describes not only the early machines of this class, but notes 
their gradual development into the splendid machines of the present day, giving the design 
and construction of the various types, forms, and special features produced by prominent 
manufacturers, American and foreign. 

Milling cutters in all their development and modernized forms are illustrated and described, 
and the operations they are capable of producing upon different classes of work are carefully 
described in detail, and the speeds and feeds necessary are discussed, and valuable and useful 
data given for determining these usually perplexing problems. The book is the most compre- 
hensive work published on the subject. 304 pages. 300 illustrations. Price . . $4.00 

" SHOP KINKS." By Robert Grimshaw. 

A book of 400 pages and 222 illustrations, being entirely different from any other book on 
machine shop practice. Departing from conventional style, the author avoids universal or 
common shop usage and limits his work to showing special ways of doing things better, more 
cheaply and more rapidly than usual. As a result the advanced methods of representative 
establishments of the world are placed at the disposal of the reader. This book shows the 
proprietor where large savings are possible, and how products may be improved. To the 
employee it holds out suggestions that, properly applied, will hasten his advancement. No 
shop can afford to be without it. It bristles with valuable wrinkles and helpful suggestions, 
it will benefit all, from apprentice to proprietor. Every machinist, at any age. should study 
its pages. Fifth Edition. Price . , % $2.50 

21 



CATALOGUE OF GOOD, PRACTICAL BOOKS 

THREADS AND THREAD CUTTING. By Colvin and Stabel. 

This clears up many of the mysteries of thread-cutting, such as double and triple threads, 
internal threads, catching threads, use of hobs, etc. Contains a lot of useful hints and several 
tables. 3rd Edition. Price 26 cents 

TOOLS FOR MACHINISTS AND WOOD WORKERS, INCLUDING INSTRUMENTS 
OF MEASUREMENT. By Joseph G. Horner. 

The principles upon which cutting tools for wood, metal, and other substances are made are 
identical, whether used by the machinist, the carpenter, or by any other skilled mechanic in 
their daily work, and the object of this book is to give a correct and practical description of 
these tools as they are commonly designed, constructed, and used. 340 pages, fully illustrated. 
Price $3.50 

MANUAL TRAINING 



ECONOMICS OF MANUAL TRAINING. By Louis Rouillion. 

The only book published that gives just the information needed by all interested in Manual 
Training, regarding Buildings, Equipment, and Supplies. Shows exactly what is needed for 
all grades of the work from the Kindergarten to the High and Normal School. Gives item- 
ized lists of everything used in Manual Training Work and tells just what it ought to cost. 
Also shows where to buy supplies, etc. Contains 174 pages, and is fully illustrated. 
2nd Edition. Price $1.50 

MARINE ENGINEERING 



MARINE ENGINES AND BOILERS, THEIR DESIGN AND CONSTRUCTION. By 

Dr. G. Bauer, Leslie S. Robertson, and S. Bryan Donkin. 

In the words of Dr. Bauer, the present work owes its origin to an oft felt want of a Condensed 
Treatise, embodying the Theoretical and Practical Rules used in Designing Marine Engines 
and Boilers. The need for such a work has been felt by most engineers engaged in the con- 
struction and working of Marine Engines, not only by the younger men, but also by those of 
greater experience. The fact that the original German work was written by the chief engineer 
of the famous Vulcan Works, Stettin, is in itself a guarantee that this book is in all respects 
thoroughly up-to-date, and that it embodies all the information which is necessary for the 
design and construction of the highest types of marine engines and boilers. It may be said, 
that the motive power which Dr. Bauer has placed in the fast German liners that have been 
turned out of late years from the Stettin Works, represent the very best practice in marine 
engineering of the present day. 

This work is clearly written, thoroughly systematic, theoretically sound; while the character 
of its plans, drawings, tables, and statistics is without reproach. The illustrations are care- 
ful reproductions from actual working drawings, with some well-executed photographic views 
of completed engines and boilers. 744 pages. 550 illustrations and numerous tables. 

$9.00 net 
MODERN SUBMARINE CHART. 

A cross-section view, showing clearly and distinctly all the interior of a Submarine of the 
latest type. You get more information from this chart, about the construction and operation 
of a Submarine, than in any other way. No Details omitted — everything is accurate and to 
scale. It is absolutely correct in every detail, having been approved by Naval Engineers. 
All the machinery and devices fitted in a modern Submarine Boat are shown and to make the 
engraving more readily understood all the features are shown in operative form with Officers 
and Men in the act of performing the duties assigned to them in service conditions. This 
CHART IS REALLY AN ENCYCLOPEDIA OP A SUBMARINE. It is educational 
and worth many times its cost. Mailed in a Tube for 25 cents 

MINING 

ORE DEPOSITS, WITH A CHAPTER ON HINTS TO PROSPECTORS. By J. P. 

Johnson 

This book gives a condensed account of the ore-deposits at present known in South Africa. 
It is also intended as a guide to the prospector. Only an elementary knowledge of geology 
and some mining experience are necessary in order to understand this work. With these 
qualifications, it will materially assist one in his search for metalliferous mineral occurrences 



22 






CATALOGUE OF GOOD, PRACTICAL BOOKS 

and, so far as simple- ores are concerned, should enable one to form some idea of the possi- 
bilities of any he may find. 

Among the chapters given are: Titaniferous and Chromiferous Iron Oxides — Nickel — Cop- 
per — Cobalt — Tin — Molybdenum — Tungsten — Lead — Mercury — Antimony — Iron — Hints to 
Prospectors $2.00 

PHYSICS AND CHEMISTRY OF MINING. By T. H. Byrom. 

A practical work for the use of all preparing for examinations in mining or qualifying for 
colliery managers' certificates. The aim of the author in this excellent book is to place clearly 
before the reader useful and authoritative data which will render him valuable assistance in 
his studies. The only work of its kind published. The information incorporated in it will 
prove of the greatest practical utility to students, mining engineers, colliery managers, and 
all others who are specially interested in the present-day treatment of mining problems. 
Among its contents are chapters on: The Atmosphere; Laws Relating to the Behavior of 
Gases; The Diffusion of Gases; Composition of the Atmosphere: Sundry Constituents of the 
Atmosphere; Water; Carbon; Fire-Damp; Combustion; Coal Dust and Its Action; Ex- 
plosives; Composition of Various Coals and Fuels; Methods of Analysis of Coal; Strata Ad- 
joining the Coal Measures; Magnetism and Electricity; Appendix; Useful Tables, etc.; 
Miscellaneous Questions. 160 pages. Illustrated $2.00 

PRACTICAL COAL MINING. By T. H. Cockin. 

An important work, containing 428 pages and 213 illustrations, complete with practical de- 
tails, which will intuitively impart to the reader, not only a general knowledge of the princi- 
ples of coal mining, but also considerable insight into allied subjects. This treatise is posi- 
tively up to date in every instance, and should be in the hands of every colliery engineer, 
geologist, mine operator, superintendent, foreman, and all others who are interested in or 
connected with the industry. 2nd Edition $2.50 

PATTERN MAKING 

PRACTICAL PATTERN MAKING. By F. W. Barrows. 

This is a very complete and entirely practical treatise on the subject of pattern making, illus- 
trating pattern work in wood and metal. From its pages you are taught just what you should 
know about pattern making. It contains a detailed description of the materials used by 
pattern makers, also the tools, both those for hand use, and the more interesting machine 
tools; having complete chapters on the band saw, The Buzz Saw, and the Lathe. Individual 
patterns of many different kinds are fully illustrated and described, and the mounting of 
metal patterns on plates for molding machines is included. 

Rules, Formulas and Tables are included, containing simple and original methods for finding 
the weight of castings, both from the pattern itself and from the drawings. This section 
contains some new and practical formulas, which will be found very useful in estimating 
weights, with the accuracy required for quotations to prospective customers. Ali of these 
rules are simple, and can be put to practical use by the ordinary, every-day man, and they 
have been proved by years of actual use. 

Plain rules for keeping down the cost of patterns, with a complete system for checking the 
cost of and marking the patterns, and a card record showing what the pattern is, material 
used, where located in safe, with its cost and date of production, is included. The book closes 
with an original and practical method for the inventory and valuation of patterns. Con- 
taining 326 pages and 150 detailed illustrations. Price $2.00 

PERFUMERY 

HENLEY'S TWENTIETH CENTURY BOOK OF RECEIPTS, FORMULAS AND PRO- 
CESSES. Edited by G. D. Hiscox. 

The most valuable Techno-chemical Receipt Book published. Contains over 10,000 practical 
receipts, many of which will prove of special value to the perfumer, a mine of information, up- 
to-date in every respect. Price, Cloth, $3.00; half morocco $4.00 

PERFUMES AND THEIR PREPARATION. By G. W. Askinson, Perfumer. 
A comprehensive treatise, in which there has been nothing omitted that could be of value 
to the Perfumer. Complete directions for making handkerchief perfumes, smelling-salts, 
sachets, fumigating pastilles: preparations for the care of the skin, the mouth, the hair, cos- 
metics, hair dyes and other toilet articles are given, also a detailed description of aromatic 
suostances: their nature, tests of purity, and wholesale manufacture. A book of general, 
as well as professional interest, meeting the wants not only of the druggist and perfume man- 
ufacturer, but also of the general public. Third edition. 312 pages. Illustrated- . $3,00 

2 3 



CATALOGUE OF GOOD, PRACTICAL BOOKS 
PLUMBING 

MECHANICAL DRAWING FOR PLUMBERS. By R. M. Starbuck. 
A concise, comprehensive and practical treatise on the subject of mechanical drawing in its 
various modern applications to the work of all who are in any way connected with fche 
plumbing trade. Nothing will so help the plumber in estimating and in explaining work to 
customers and workmen as a knowledge of drawing, and to the workman it is of inestimable 
value if he is to rise above his position to positions of greater responsibility. Among the 
chapters contained are: 1. Value to plumber of knowledge of drawing; tools required 
and their use; common views needed in mechanical drawing. 2. Perspective versus mechan- 
ical drawing in showing plumbing construction. 3. Correct and incorrect methods in 
plumbing drawing; plan and elevation explained. 3. Floor and cellar plans and elevation; 
scale drawings; use of triangles. 5. Use of triangles; drawing of fittings, traps, etc. 6. 
Drawing plumbing elevations and fittings. 7. Instructions in drawing plumbing elevations. 
8. The drawing of plumbing fixtures ; scale drawings. 9. Drawing of fixtures and fittings. 
10. Inking of drawings. 11. Shading of drawings. 12. Shading of drawings. 13. Sec- 
tional drawings; drawing of threads. 14. Plumbing elevations from architect's plan. 
15. Elevations of separate parts of the plumbing system. 16. Elevations from architect's 
plans. 17. Drawing of detail plumbing connections. 18. Architect's plans and plumbing 
elevations of residence. 19. Plumbing elevations of residence (continued) ; plumbing plans 
for cottage. 20. Plumbing elevations; roof connections. 21. Plans and plumbing eleva- 
tions for six-flat building. -22. Drawing of various parts of the plumbing system; use of 
scales. 23. Use of architect's scales. 24. Special features in the illustrations of country 
plumbing. 25. Drawing of wrought iron piping, valves, radiators, coils, etc. 26. Drawing 
of piping to illustrate heating systems. 150 illustrations. Price $1.50 

MODERN PLUMBING ILLUSTRATED. By R. M. Starbuck. 

This book represents the highest standard of plumbing work. It has been adopted and used 
as a reference book by the United States Government, in its sanitary work in Cuba, Porto 
Rico, and the Philippines, and by the principal Boards of Health of the United States and 
Canada. 

It gives connections, sizes and working data for all fixtures and groups of fixtures. It is 
helpful to the master plumber in demonstrating to his customers and in figuring work. It 
gives the mechanic and student quick and easy access to the best modern plumbing practice. 
Suggestions for estimating plumbing construction are contained in its pages. This book 
represents, in a word, the latest and best up-to-date practice, and should be in the hands of 
every architect, sanitary engineer and plumber who wishes to keep himself up to the minute 
on this important feature of construction. Contains foUowing chapters, each illustrated 
with a full-page plate: Kitchen sink, laundry tubs, vegetable wash sink; lavatories, 
pantry sinks, contents of marble slabs; bath tub, foot and sitz bath, shower bath; water 
closets, venting of water closets; low-down water r closets, water closets operated by flush 
valves, water closet range; slop sink, urinals, the bidet; hotel and restaurant sink, grease 
trap; refrigerators, safe wastes, laundry waste; lines of refrigerators, bar s ink s, soda foun- 
tain sinks; horse stall, frost-proof water closets; connections for S traps, venting; con- 
nections for drum traps; soil pipe connections; supporting of soil pipe; main trap and 
fresh air inlet; floor drains and cellar drains, subsoil drainage; water closets and floor 
connections; local venting; connections for bath rooms ; connections for bath rooms, con- 
tinued; connections for bath rooms, continued; connections for bath rooms, continued; 
examples of poor practice; roughing- work ready for test; testing of plumbing system; 
method of continuous venting; continuous venting for two-floor work; continuous venting 
for two lines of fixtures on three or more floors ; continuous venting of water closets ; plumb- 
ing for cottage house ; construction for cellar piping ; plumbing for residence, use of special 
fittings; plumbing for two-flat house; plumbing for apartment building; plumbing for 
double apartment building; plumbing for office building; plumbing for public toilet rooms; 
plumbing for public toilet rooms, continued; plumbing for bath establishment; plumbing 
for engine house, factory plumbing ; automatic flushing for schools, factories, etc. ; use of 
flushing valves; urinals for public toilet rooms; the Durham system, the destruction of 
pipes by electrolysis; construction of work without use of lead; Automatic sewage lift, 
automatic sump tank; country plumbing; construction of cesspools; septic tank and auto- 
matic sewage siphon; country plumbing; water supply for country house; thawing of 
water mains and service by electricity; double boilers; hot water supply of large build- 
ings ; automatic control of hot water tank ; suggestions for estimating plumbing construc- 
tion. 400 octavo pages, fully illustrated by 55 full-page engravings. Price . $4.00 

STANDARD PRACTICAL PLUMBING. By R. M. Starbuck. 

A complete practical treatise of 450 pages covering the subject of Modern Plumbing 
in all its branches, a large amount of space being devoted to a very complete and practical 
treatment of the subject of Hot Water Supply and Circulation and Range Boiler Work. 
Its thirty chapters include about every phase of the subject one can think of, making it 

24 



CATALOGUE OF GOOD, PRACTICAL BOOKS 

1 — 

an indispensable work to the master plumber, the journeyman plumber, and the apprentice 
plumber, containing chapters on: the plumber's tools; wiping solder, composition and use; 
joint wiping; lead work; traps; siphonage of traps; venting; continuous venting; house 
sewer and sewer connections; house drain; soil piping, roughing; main trap and fresh air 
inlet; floor, yard, cellar drains, rain leaders, etc. ; fixture wastes: water closets ; ventilation; 
improved plumbing connections; residence plumbing; plumbing for hotels, schools, fac- 
tories, stables, etc.; modern country plumbing; filtration of sewage and water supply; 
hot and cold supply; range boilers; circulation; circulating pipes; range boiler problems; 
hot water for large buildings; water lift and its use; multiple connections for hot water 
boilers; heating of radiation by supply system; theory for the plumber; drawing for the 
plumber. Fully illustrated by 347 engravings. Price $3.00 

RECEIPT BOOK 

HENLEY'S TWENTIETH CENTURY BOOK OF RECEIPTS, FORMULAS AND PRO- 
CESSES. Edited by Gardner D. Hiscox. 

The most valuable Techno-chemical Receipt Book published, including over 10,000 selected 
scientific, chemical, technological, and practical receipts and processes. 

This is the most complete Book of Receipts ever published, giving thousands of receipts for 
the manufacturer of valuable articles for everyday use. Hints, Helps, Practical Ideas, and 
Secret Processes are revealed within its pages. It covers every branch of the useful arts and 
tells thousands of ways of making money and is just the book everyone should have at his 
command. 

Modern in its treatment of every subject that properly falls within its scope, the book may 
truthfully be said to present the very latest formulas to be found in the arts and industries 
and to retain those processes which long experience has proven worthy of a permanent record. 
To present here even a limited number of the subjects which find a place in this valuable 
work would be difficult. Suffice to say that in its pages will be found matter of intense in- 
terest and immeasurable practical value to the scientific amateur and to him who wishes to 
obtain a knowledge of the many processes used in the arts, trades and manufactures, a 
knowledge which will render his pursuits more instructive and remunerative. Serving as a 
reference book to the small and large manufacturer and suppplying intelligent seekers with 
the information necessary to conduct a process, the work will be found of inestimable worth 
to the Metallurgist, the Photographer, the Perfumer, the Painter, the Manufacturer of 
Glues, Pastes, Cements, and Mucilages, the Compounder of Alloys, the Cook, the Physician, 
the Druggist, the Electrician, the Brewer, the Engineer, the Foundryman, the Machinist, 
the Potter, the Tanner, the Confectioner, the Chiropodist, the Manicure, +<he Manufacturer 
of Chemical Novelties and Toilet Preparations, the Dyer, the Electroplater, the Enameler, 
the Engraver, the Provisioner, the Glass Worker, the Goldbeater, the Watchmaker, the Jew- 
eler, the Hat Maker, the Ink Manufacturer, the Optician, the Farmer, the Dairyman, the 
Paper Maker, the Wood and Metal Worker, the Chandler and Soap Maker, the Veterinary 
Surgeon, and the Technologist in general. 

A mine of information, and up-to-date in every respect. A book which will prove of value 
to EVERYONE, as it covers every branch of the Useful Arts. 800 pages. Price $3.00 

WHAT IS SAID OF THIS BOOK: 



" Your Twentieth Century Book of Receipts, Formulas and Processes duly received. I am 
glad to have a copy of it, and if I could not replace it money couldn't buy it. It is the best 
thing of the sort I ever saw." (Signed) M. E. Trux, 

Sparta, Wis. 
•' There are few persons who would not be able to find in the book some single formula that 
would repay several times the cost of the book." — Merchant's Record and Show Window. 

RUBBER 



RUBBER HAND STAMPS AND THE MANIPULATION OF INDIA RUBBER. By 
T. O'Conor Sloane. 

This book gives full details on all points, treating in a concise and simple manner the elements 
of nearly everything it is necessary to understand for a commencement in any branch of the 
India Rubber Manufacture. The making of all kinds of Rubber Hand Stamps, Small Articles 
of India Rubber, IT. S. Government Composition, Dating Hand Stamps, the Manipulation 
of Sheet Rubber, Toy Balloons, India Rubber Solutions, Cements, Blackings, Renovating 

25 



CATALOGUE OF GOOD, PRACTICAL BOOKS 






Varnish, and Treatment for India Rubber Shoes, etc.; the Hektograph Stamp Inks, and 
Miscellaneous Notes, with a Short Account of the Discovery, Collection, and Manufacture of 
India Rubber are set forth in a manner designed to be readily understood, the explanations 
being plain and simple. Including a chapter on Rubber Tire Making and Vulcanizing ; also a 
chapter on the uses of rubber in Surgery and Dentistry. Third revised and enlarged edition. 
175 pages. Illustrated $1.00 

SAWS 

SAW FILINGS AND MANAGEMENT OF SAWS. By Robert Grimshaw. 

A practical hand book on filing, gumming, swaging, hammering, and the brazing of band saws, 
the speed, work, and power to run circular saws, etc. A handy book for those who have charge 
of saws, or for those mechanics who do their own filing, as it deals with the proper shape and 
pitches of saw teeth of all kinds and gives many useful hints and rules for gumming, setting, 
and filing, and is a practical aid to those who use saws for any purpose. New edition, revised 
and enlarged. Illustrated. Price $1.00 

STEAM ENGINEERING 

AMERICAN STATIONARY ENGINEERING. By W. E. Crane. 

This book begins at the boiler room and takes in the whole power plant. A plain talk on 
every-day work about engines, boilers, and their accessories. It is not intended to be scien- 
tific or mathematical. All formulas are in simple form so that any one understanding plain 
arithmetic can readily understand any of them. The author has made this the most prac- 
tical book in print; has given the results of his years of experience, and has included about 
all that has to do with an engine room or a power plant. You are not left to guess at a single 
point. You are shown clearly what to expect under the various conditions ; how to secure 
the best results; ways of preventing "shut downs" and repairs; in short, all that goes to 
make up the requirements of a good engineer, capable of taking charge of a plant. It's plain 
enough for practical men and yet of value to those high in the profession. 
A. partial list of contents is: The boiler room, cleaning boilers, firing, feeding; pumps; 
inspection and repair ; chimneys, sizes and cost; piping; mason work; foundations; testing 
eement; pile driving; engines, slow and high speed; valves; valve setting ; Corliss engines, 
setting valves, single and double eccentric; air pumps and condensers; different types of 
condensers; water needed; lining up; pounds; pins not square in crosshead or crank; 
engineers' tools ; pistons and piston rings ; bearing metal ; hardened copper ; drip pipes from 
cylinder jackets; belts, how made, care of; oils; greases; testing lubricants; rules and 
tables, including steam tables; areas of segments ; squares and square root; cubes and cube 
root; areas and circumferences of circles. Notes on: Brick work; explosions ;i pumps; 
pump valves; heaters, economizers ; safety valves ; lap. lead, and clearance. Has a complete 
examination for a license, etc., etc. Second edition. 285 pages. Illustrated. Price . $2.00 

EMINENT ENGINEERS. By Dwight Goddard. 

Everyone who appreciates the effect of such great inventions as the Steam Engine, Steamboat, 
Locomotive, Sewing Machine, Steel Working, and other fundamental discoveries, is interested 
in knowing a little about the men who made them and their achievements. 
Mr. Goddard has selected thirty-two of the world's engineers who have contributed most 
largely to the advancement of our civilization by mechanical means, giving only such facts as 
are of general interest and in a way which appeals to all, whether mechanics or not. 280 
pages. 35 illustrations. Price $1.50 

ENGINE RUNNER'S CATECHISM. By Robert Grimshaw. 

A practical treatise for the stationary engineer, telling how to erect, adjust and run the prin- 
cipal steam engines in use in the United States. Describing the principal features of various 
special and well-known makes of engines: Temper Cut-off, Shipping and Receiving Founda- 
tions, Erecting and Starting, Valve Setting, Care and Use, Emergencies, Erecting and Ad- 
justing Special Engines. 

The questions asked throughout the catechism are plain and to the point ."and the ansvyers 
are given in such simple language as to be readily understood by anyone. All the instructions 
given are complete and up-to-date; and they are written in a popular style, without any 
technicalities or mathematical formulae. The work is of a handy size for the pocket, clearly 
and well printed, nicely bound, and profusely illustrated. To young engineers this catechism 

26 



CATALOGUE OF GOOD, PRACTICAL BOOKS 

will be of great value., especially to those who may be preparing to go forward to be examined 
for certificates of competency; and to engineers generally it will be of no little service, as they 
will find in this volume more really practical and useful information than is to be found any- 
where else within a like compass. 387 pages. Seventh edition. Price .... $2.00 

ENGINE TESTS AND BOILER EFFICIENCIES. By J. Buchetti. 
This work fully describes and illustrates the method of testing the power of steam engines, 
turbines and explosive motors. The properties of steam and the evaporative power of fuels. 
Combustion of fuel and chimney draft; with formulas explained or practically computed 
255 pages, 179 illustrations $3.00 

HORSEPOWER CHART. 

Shows the horsepower of any stationary engine without calculation. No matter what the 
cylinder diameter of stroke; the steam pressure or cut off; the revolutions, or whether con- 
densing or non-condensing, it's all there. Easy to use, accurate, and saves time and calcu- 
lations. Especially useful to engineers and designers 50 cents 

MODERN STEAM ENGINEERING IN THEORY AND PRACTICE. By Gardner 
D. Hiscox. 

This is a complete and practical work issued for Stationary Engineers and firemen dealing 
with the care and management of boilers, engines, pumps, superheated steam, refrigerating 
machinery, dynamos, motors, elevators, air compressors, and all other branches with which 
the modern engineer must be familiar. Nearly 200 questions with their answers on steam 
and electrical engineering, likely to be asked by the Examining Board, are included. 
Among the chapters are: Historical; steam and its properties; appliances for the genera- 
tion of steam; types of boilers; chimney and its work; heat economy of the feed water; 
steam pumps and their work; incrustation and its work; steam above atmospheric pressure; 
flow of steam from nozzles ; superheated steam and its work ; adiabatic expansion of steam ; 
indicator and its work; steam engine proportions; slide valve engines and valve motion; 
Corliss engine and its valve gear; compound engine and its theory; triple and multiple 
expansion engine, steam turbine; refrigeration; elevators and their management; cost 
of power; steam engine troubles; electric power and electric plants. 487 pages. 405 en- 
gravings. Price $3.00 

STEAM ENGINE CATECHISM. By Robert Grimshaw. 

This unique volume of 413 pages is not only a catechism on the question and answer princi- 
ple; but it contains formulas and worked-out answers for all the Steam problems that apper- 
tain to the operation and management of the Steam Engine. Illustrations of various valves 
and valve gear with their principles of operation are given. Thirty-four Tables that are 
indispensable to every engineer and fireman that wishes to be progressive and is ambitious to 
become master of his calling are within its pages. It is a most valuable instructor in the 
service of Steam Engineering. Leading engineers have recommended it as a valuable educa- 
tor for the beginner as well as a reference book for the engineer. It is thoroughly indexed 
for every detail. Every essential question on the Steam Engine with its answer is contained 
in this valuable work. Sixteenth edition. Price $2.00 

STEAM ENGINEER'S ARITHMETIC. By Colvin-Cheney. 

A practical pocket book for the steam engineer. Shows how to work the problems of the 
engine room and shows "why." Tells how to figure horse-power of engines and boilers; area 
of boilers ; has tables of areas and circumferences ; steam tables ; has a dictionary of engineering 
terms. Puts you on to all all of the little kinks in figuring whatever there is to figure around 
a power plant. Tells you about the heat unit; absolute zero; adiabatic expansion; duty of 
engines; factor of safety; and 1,001 other things; and everything is plain and simple — not 
the hardest way tc figure, but the easiest. 2nd Edition 50 cents 

STEAM HEATING AND VENTILATION 



HOT-WATER HEATING AND VENTILATION. By A. G. 

King. 

This book is the standard and latest work published on the subject and has been prepared for 
the use of all engaged in the business of steam, hot water heating, and ventilation. It is an 
original and exhaustive work. Tells how to get heating contracts, how to install heating and 
ventilating apparatus, the best business methods to be used, with "Tricks of the Trade" for 

27 



CATALOGUE OF GOOD, PRACTICAL BOOKS 



shop use. Rules and data for estimating radiation and cost and such tables and information 
as make it an indispensable work for everyone interested in steam, hot water heating, and venti- 
lation. It describes all the principal systems of steam, hot water, vacuum, vapor, and vacuum- 
vapor heating, together with the new accelerated systems of hot water circulation, including 
chapters on up-to-date methods of ventilation and the fan or blower system of heating and 
ventilation. Containing chapters on: I. Introduction. II. Heat. III. Evolution of 
artificial heating apparatus. IV. Boiler surface and settings. V. The chimney flue. VI. 
Pipe and fittings. VII. Valves, various kinds. VIII. Forms of radiating surfaces. IX. 
Locating of radiating surfaces. X. Estimating radiation. XI. Steam-heating apparatus. 
XII. Exhaust-steam heating. XIII. Hot-water heating. XIV. Pressure systems of hot- 
water work. XV. Hot-water appliances. XVI. Greenhouse heating. XVII. Vacuum 
vapor and vacuum exhaust heating. XVIII. Miscellaneous heating. XIX. Radiator and 
pipe connections. XX. Ventilation. XXI. Mechanical ventilation and hot-blast heating. 
XXII. Steam appliances. XXIII. District heating. XXIV. Pipe and boiler covering. 
XXV. Temperature regulation and heat control. XXVI. Business methods. XXVII. 
Miscellaneous. XXVIII. Rules, tables and useful information. 367 pages. 300 detailed 
engravings. Price $3.00 

STEAM PIPES 



STEAM PIPES: THEIR DESIGN AND CONSTRUCTION. By Wm. H. Booth. 

The work is well illustrated in regard to pipe joints, expansion offsets, flexible joints, and 
self-contained sliding joints for taking up the expansion of long pipes. In fact, the chapters 
on the flow of steam and expansion of pipes are most valuable to all steam fitters and users. 
The pressure strength of pipes and method of hanging them are well treated and illustrated. 
Valves and by-passes are fully illustrated and described, as are also flange joints and their 
proper proportions, exhaust heads and separators. One of the most valuable chanters is that 
on superheated steam and the saving of steam by insulation with the various kinds of felt- 
ing and other materials- with comparison tables of the loss of heat in thermal units from naked 
and felted steam pipes. Contains 187 pages. Price $2.00 

STEEL 

AMERICAN STEEL WORKER. By E. R. Markham. 

This book tells how to select, and how to work, temper, harden, and anneal steel for everything 
on earth. It doesn't tell how to temper one class of tools and then leave the treatment of 
another kind of tool to your imagination and judgment, but it gives careful instructions for 
every detail of every tool, whether it be a tap, a reamer or just a screw-driver. It tells about 
the tempering of small watch springs, the hardening of cutlery, and the annealing of dies. In 
fact there isn't a thing that a steel worker would want to know that isn't included. It is the 
standard book on selecting, hardening, and tempering all grades of steel. Among the 
chapter headings might be mentioned the following subjects: Introduction; the workman; 
steel; methods of heating ; heating tool steel; forging; annealing; hardening baths; baths 
for hardening; hardening steel; drawing the temper after hardening; examples of hard- 
ening; pack hardening; case hardening; spring tempering; making tools of machine steel; 
special steels; steel for various tools; causes of trouble; high speed steels, etc. 366 pages. 
Very fully illustrated. 3rd Edition. Price $2.50 

HARDENING, TEMPERING, ANNEALING, AND FORGING OF STEEL. By J. V. 

WOODWORTH. 

A new work treating in a clear, concise manner all modern processes for the heating, annealing 
forging, welding, hardening, and tempering of steel, making it a book of great practical value 
to the metal-working mechanic in general, with special directions for the successful hardening 
and tempering of all steel tools used in the arts, including milling cutters, taps, thread dies, 
reamers, both solid and shell, hollow mills, punches and dies, and all kinds of sheet metal 
working tools, shear blades, saws, fine cutlery, and metal cutting tools of all description, as 
well as for all implements of steel both large and small. In this work the simplest and most 
satisfactory hardening and tempering processes are given. 

The uses to which the leading brands of steel may be adapted are concisely presented, and their 
treatment for working under different conditions explained, also the special methods for the 
hardening and tempering of special brands. 

A chapter devoted to the different processes for Case-hardening is also included, and special 
reference made to the adoption of machinery steel for tools of various kinds. 4th Edition. 288 
pages. 201 Illustrations. Price $2.50 

28 



CATALOGUE OF GOOD, PRACTICAL BOOKS 



TURBINES 

MARINE STEAM TURBINES. By Dr. G. Bauer and 0. Lasche. Assisted by 
E. Ludwig and H. Vogel. Translated from the German and edited by M. G. S. 
Swallow. 

This work forms a supplementary volume to the book entitled " Marine Engines and Boilers." 
The authors of this book, Dr. G. Bauer and O. Lasche, may be regarded as the leading 
authorities on turbine construction. 

The book is essentially practical and discusses turbines in which the full expansion of steam 
passes through a number of separate turbines arranged for driving two or more shafts, as 
in the Parsons system, and turbines in which the complete expansion of steam from inlet 
to exhaust pressure occurs in a turbine on one shaft, as in the case of the Curtis machines. 
It will enable a designer to carry out all the ordinary calculations necessary for the con- 
struction of steam turbines, hence it fills a want which is hardly met by larger and more 
theoretical works. 

Numerous tables, curves and diagrams will be found, which explain with remarkable lucidity 
the reason why turbine blades are designed as they are, the course which steam takes through 
turbines of various types, the thermodynamics of steam turbine calculation, the influence 
of vacuum on steam consumption of steam turbines, etc. In a word, the very information 
which a designer and builder of steam turbines most requires. The book is divided into 
parts as follows: 1. Introduction. 2. General remarks on the design of a turbine installa- 
tion. 3. The calculation of steam turbines. 4. Turbine design. 5. Shafting and pro- 
pellers. 6. Condensing plant. 7. Arrangement of turbines. 8. General remarks on the 
arrangement of steam turbines in steamers. 9. Turbine-driven auxiliaries. 10. Tables. 
Large octavo. 214 pages. Fully illustrated and containing 18 tables. Including an entropy 
chart. Price, net, $3.50 

WATCH MAKING 

WATCHMAKER'S HANDBOOK. By Claudius Saunier. 

This famous work has now reached its seventh edition and there is no work issued that can 
compare to it for clearness and completeness. It contains 498 pages and is intended as a 
workshop companion for those engaged in Watch-making and allied Mechanical Arts. Nearly 
250 engravings and fourteen plates are included. Price ... .... $3.00 



29 



The Most Valuable Techno-Chemical Receipt Book Published 

Henley's Twentieth Century Book of 

RECIPES 

FORMULAS 

AND PROCESSES 




4' &% 



Edited by GARDNER D. HISCOX, M.E. 



Price $3.00 Cloth Binding $4.00 Half Morocco Binding 
800 Large Octavo (6 x 9 T A) Pages 

Contains over 10,000 Selected Scientific, Chemical, Technological an c 

Practical Recipes and Processes, including hundreds of so-called 

Trade Secrets for every business 

To present here even a limited number of the subjects which find a place in this valuable 
work would be difficult. Suffice to say that in its pages will be found matter of intense interest 
and immeasurable practical value to the scientific amateur and to him who wishes to obtain a 
knowledge of the many processes used in the arts, trades and manufactures, a knowledge which 
will render his pursuits more instructive and remunerative. Serving as a reference book to the 
small and large manufacturer and supplying intelligent seekers with the information neces- 
sary to conduct a process, the work will be found of inestimable worth to the Metallurgist, tie 
Photographer, the Perfumer, the Painter, the Manufacturer of Glues, Pastes, Cements, ani 
Mucilages, the Compounder of Alloys, the Cook, the Physician, the Druggist, the Electrician, 
the Brewer, the Engineer, the Foundryman, the Machinist, the Potter, the Tanner, the Confec- 
tioner, the Chiropodist, the Manicure, the Manufacturer of Chemical Novelties and Toilet 
Preparations, the Dyer, the Electroplater, the Enameler, the Engraver, the Provisioner, the 
Glass Worker, the Goldbeater, the Watchmaker and Jeweler, the Hat Maker, the Ink Manu- 
facturer, the Optician, the Farmer, the Dairyman, the Paper Maker, the Wood and Metal 
Worker, the Chandler and Soap Maker, the Veterinary Surgeon, and the Technologist in general. 



Bleaching Recipes 

Etching and Engraving Recipes 

Recipes for Glass Making 

Paper Making Recipes 

Recipes for Ointments 

Mirror-Making Formulas 

Paint Making Formulas 

Gilding Recipes 

Galvanizing Recipes 

Bronzing Recipes 

Tinning Recipes 

Silvering Recipes 

Recipes for Adhesives 

Recipes for Plating and Enameling 

Cleaning Processes 



Among the Recipes given are, 



Soap Making 

Leather and its Preparation 

Recipes for Alloys 

Recipes for Solders 

Photographic Formulas 

Shoe Dressing Recipes 

Stove Blacking Recipes 

Rust Preventive Recipes 

Recipes for Lubricants 

Recipes for Oils 

Recipes for Dyes, Colors, and PigmeDts 

Recipes for Dryers 

Ink Recipes 

Recipes for Artificial Gem Making 

Jewelers' and Watchmakers' Recipes 



Household Formulas 

Waterproofing Recipes 

Fireproofing Recipes 

Recipes for Cements, Glues, MucilsjjM 

Fireworks Recipes 

Recipes for Eradicators 

Alcohol and its Uses 

Recipes for Essences and Extract! 

Dentifrice Recipes 

Cosm-tic Recipes 

Perfume Recipes 

Tanning Recipes 

Metallurgical Formulas 

Hair Restorers 

Depilatories 



And many thousands more— Equally Important In the Arts and Manufactures 



MAR 11 1913 




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